he program was renowned for the vast array of hair styles adopted by the characters. Head Hair Designer Michael Reitz was nominated for Outstanding Hairstyling for a Series at the Emmys 5 years in a row (2002–2006); as well as 3 nominations and 1 win at the Hollywood Makeup Artist and Hair Stylist Guild Awards.

Notable contributions to the hair stylist team include:

• Karen Bartek (3 Emmy Award nominations)
• Julie Woods (1 Emmy Award nomination)
• Grace Hernandez (1 Emmy Award nomination)
• Kathrine Rees (1 Emmy Award nomination)
• Yesmin Osman (1 Emmy Award nomination)

Alias was also known for the variety of its costumes. USA Today wrote that the show "features the most outrageous array of sexy costumes since Cher went off the air".[9] Laura Goldsmith was the costume designer[9] and she received one Costume Designers Guild Award nomination.[10]

though Alias was never considered a major "hit", its series run began during a time when the ABC television network was in decline, after Who Wants to Be a Millionaire saw its ratings plummet. In fact, Alias was one of the first shows to be placed in one of the old Who Wants to Be a Millionaire timeslots, which were Sunday nights at 9:00 p.m. in late 2001. For its first two seasons, family-friendly program The Wonderful World of Disney served as Alias' incompatible lead-in.[19] Unlike many of the programs on ABC from 2001 to 2003, Alias was a series that garnered critical buzz,[citation needed] a cult following,[citation needed] and decent viewing numbers in the advertiser-friendly age 18–49 demographic. This led to ABC keeping the series on its schedule for 5 years.

The season 2 episode "Phase One" aired as a lead-out for Super Bowl XXXVII. Despite earning critical acclaim from USA Today,[20] and achieving series-high ratings of 17.4 million viewers, it was unable to fully benefit from the post-Super Bowl time slot due to ABC airing a 40-minute post-game show (unusually long even by Super Bowl standards), which pushed its start time past 11:00 p.m. ET.[21] The episode retained only 19 percent of the Super Bowl audience, and has the dubious distinction of earning the lowest overall ratings for a program airing after a Super Bowl since at least 1987, and the lowest rating ever (8.3 rating) in the age 18–49 demographic for a post-Super Bowl program,[21] until Elementary in 2013.[22]

Its ratings peak was reached in its fourth season, when ABC moved the program to Wednesday, in a 9:00 p.m. time slot following another (yet more successful) J. J. Abrams' drama, Lost,[19] while airing the season's episodes in (almost) consecutive weeks beginning with the January 5, 2005, 2-hour season premiere (watched by 15.8 million viewers;[23] the second most-watched episode in the series) and ending in May 2005. However, the fourth season was the only season in which this near-consecutive-week schedule was used, and the increase in audience numbers was minimal, as it faced competition from the results broadcasts of season 4 of American Idol, then nearing the peak of its popularity.

Coming off its most-watched season, Alias was moved to Thursdays at 8:00 p.m. in the fall of 2005 by ABC in an effort to invigorate the network's weak Thursday-night lineup. However, the move proved unsuccessful for the series, receiving the lowest viewership in the show's history. Alias became another scripted show in the history of ABC to not survive more than a year in this timeslot since Mork & Mindy was cancelled in 1982.[24] In November 2005, ABC announced that the current fifth season of Alias would be its final one.[25][26] ABC then temporarily aired Alias on Wednesdays at 10 p.m. in December, receiving the lead-in support of Lost.[27]

The ABC network gave the show a 4-month hiatus (allowing Jennifer Garner to give birth to her first child); however, when it was brought back in April 2006, its new time slot was Wednesdays at 8:00 p.m. Notwithstanding, the viewer numbers still remained dismal, culminating in a 2-hour series finale airing on Monday, May 22, 2006 (broadcast against both the season finales of the hit dramas, Fox's 24 and CBS' CSI: Miami) which attracted 6.68 million viewers.[28] In comparison, the first season averaged 9.7 million viewers.[29]

• Family: Describing the family aspects of the show, Garner stated that Alias is about "this woman and her father and trying to figure out what is always a complicated relationship in the context of life and death at work."[7]
• Prophecy: A good deal of Alias revolves around the prophecies of Milo Rambaldi. The viewer is first introduced to a prophecy about a woman who will "render the greatest power unto utter desolation".[8] Later, as Sloane completes part of the Rambaldi prophecy he has received his own prophetic message. The Rambaldi storyline seemed to come to a close with the conclusion of Elena Derevko's endgame at the end of season four, but the fifth season introduced its own "prophet" (also in pursuit of Rambaldi) in the form of the mysterious organization known as Prophet Five, which ended up being a reference to Rambaldi and the final part of his endgame, immortality, which had been set up in the first season, though this was only one part of his plan. The first part was world peace, which Elena Derevko perverted and attempted in Season 4.[8]
• Trust and betrayal: Much of the first three seasons of the show revolved around issues of trust and betrayal. Most obvious is the betrayal of Sydney by SD-6 which starts the show. However, the show includes numerous other examples of betrayal including Irina's betrayal of Jack, Sloane's betrayal of the Alliance, Sydney's betrayal of SD-6 and Sydney's lying to her friends. The first season can be viewed as a story of Sydney learning to trust her father and the second season can be viewed as Sydney struggling with trust issues relating to her mother.[8]
• Clandestine operations: The government agencies that Sydney works for are conducting secret operations in various countries regularly. The same applies of course to the mentioned illegal agencies which are battled against. Those clandestine operations deal with collecting the sought-after Rambaldi artifacts, but also with aspects like illegal arms trade or blackmailing. To further their objectives, the CIA or APO, respectively, arrest criminals from other countries and bring them to interrogation facilities of the CIA.[

lias is unusual for an American drama series in that the opening credits do not run until the end of the first long act, sometimes as late as 19 minutes into the episode. In some respects, this mimics the James Bond films, which likewise feature sometimes-lengthy pre-credits sequences. Depending on the demands of a particular episode, the credit sequence is occasionally dropped as the actor credits play over a scene; on those occasions, the series title does not appear on screen until the final fade out.

As the opening credits appear, the letters in the Alias reference flash in negative form one by one. The "S" is the last letter to appear, this time in permanent negative. In virtually every episode, the title of a city or town location will slowly zoom in, with one letter being shown in negative and a specific scene appearing within that negative. As it usually does with the "S" in the show title at the very start, this letter eventually takes up the entire screen and gives way to the scene itself.

The first three seasons used a minimalist credit sequence consisting only of the actors names appearing as the title Alias gradually forms in one corner of an otherwise black screen. For one frame in Seasons 1 and 3 during Victor Garber's credit, the Rambaldi "eye" symbol ( <o> ) flashes over the Alias title, accompanied by a short "whooshing" sound; In Season 2, it flashes during Lena Olin's credit. In season 5 it flashes during Balthazar Getty's credit.

For the fourth season, a shorter, flashier credit sequence was introduced that used a new, remixed version of the theme. As the cast names appeared, 52 images of Sydney in 47 various disguises appear in rapid succession, ending with a shot from the third-season premiere of her shooting a miniature grenade launcher.

For the fifth season, another credit sequence was designed, as the previous version was criticized for making it difficult to read the actors' names (since the eye was drawn to the many images of Jennifer Garner) and for focusing exclusively on Garner. Now for the first time, the actors are shown on screen as their names appear. The same remix of the theme music from the previous year is utilized. Also, the flashing of the letters when ALIAS is spelled out is actually in Morse code. The flashing translates to AGENT KANE (who was a character in the 2nd season played by Faye Dunaway). During the first half of the season, Elodie Bouchez appeared in the opening credits, but beginning with the episode "S.O.S." her credit was changed to a "special guest star" credit outside the opening sequence and Amy Acker was added to the opening credits in place of Bouchez.

Most episodes in the first season included a prologue narrated by Sydney Bristow, setting up the premise of the series. In the first half of season two this was replaced by a voiceover by Greg Grunberg (who plays Agent Weiss) and later in season 2 was dropped entirely.

Produced by Touchstone Television and Bad Robot Productions, film production primarily took place in the greater Los Angeles area. Studio shooting primarily took place at the Walt Disney Studios in Burbank, California, along with some outdoor shots near some of the studio's famous buildings (such as the original Animation Building or the ABC building, which appeared as a building in Hong Kong in the season 1 episode "The Coup"). Despite its worldwide locales, only one episode was ever filmed outside the Los Angeles region, in Las Vegas, Nevada.

• J. J. Abrams – executive producer
• John Eisendrath – executive producer (Season 1–3)
• Alex Kurtzman – executive producer (Season 2–3)
• Roberto Orci – executive producer (Season 2–3)
• Jeffrey Bell – executive producer (Season 4–5)
• Jeff Pinkner – executive producer (Season 5)
• Jesse Alexander – executive producer (Season 5)

Alias featured an ensemble cast portraying the various people in Sydney's life. During the course of the series, every main character becomes involved in the world of espionage in some form or another.

• Sydney Bristow (Jennifer Garner) daughter of Jack Bristow and Irina Derevko is a graduate student in English in Los Angeles. She moonlights as an operative for SD-6, which she initially believed was a black ops division of the CIA. Her fiancé was murdered in the pilot episode, and she then learned SD-6 is actually a branch of an international criminal organization known as the Alliance of Twelve. She then becomes a double agent for the real CIA. She would later become a member of APO, a black-ops division of the CIA. Sydney has 41 confirmed kills through the series.
• Arvin Sloane (Ron Rifkin) was the head of SD-6 and APO, the show's main antagonist. Originally a loyal CIA officer, he is obsessed with the work of a 15th-century prophet, Milo Rambaldi. Though sometimes showing a genuine affection to the Bristows, he is always ready to hurt them and even kill them, and vice versa.
• Michael Vaughn (Michael Vartan) was Sydney's CIA handler and later partner. He and Sydney share a mutual attraction, which eventually leads to a relationship. At the end of Season 4, it is revealed that it was not a coincidence that he met Sydney. Despite departing in season 5 as a series regular, Vartan's character was still credited as a main cast member in the first episode then special guest star in the latter part of the season.
• Will Tippin (Bradley Cooper) was a reporter for a local newspaper and is one of Sydney's two best friends. After the death of Sydney's fiancé, Will begins to investigate and eventually learns of the existence of SD-6. The discovery threatens his life but he later is recruited as an analyst for the CIA. He is put into witness protection at the beginning of Season three. The character makes occasional guest appearances in later seasons.
• Francie Calfo (Merrin Dungey) is Sydney's other best friend. When Season 1 begins, she is Sydney's roommate and fellow graduate student. In Season 2, she drops out of her graduate program and opens a restaurant in the Silver Lake neighborhood of Los Angeles. She remains largely unaware of the spy world until the middle of season two when she is killed and her identity is stolen by a doppelgänger. She (and her double) also dated Will during the second season.
• Marcus Dixon (Carl Lumbly) is Sydney's partner and friend at SD-6. He is the first one to notice signs of Sydney's betrayal, but dismisses his thoughts as foolish. During the two-year gap between the second and third season, he became a director at the CIA. However, he later resigns as he thinks the office job just is not for him. Dixon later joins APO.
• Marshall Flinkman (Kevin Weisman) worked in tech support at SD-6. He takes up the same role in the CIA and at APO. Even though he is not field-trained, he has participated in missions on several occasions.
• Jack Bristow (Victor Garber) is Sydney's father and also works for SD-6 but is actually a double agent for the CIA. In Season 1, his relationship with Sydney is strained. He was devastated by her mother's "death" and kept Sydney at arm's length for the rest of her childhood. As a CIA agent, he is exceptionally ruthless and skillful as evidenced by his CIA call sign Raptor. After Sloane left, Jack took over as head of APO.
• Eric Weiss (Greg Grunberg) is a friend of Vaughn's and also a CIA agent. He later forges a relationship with Sydney's sister, Nadia. Against his over-the-top colleagues, he keeps a more human and gentle demeanor.
• Julian Sark (David Anders) is originally introduced as an operative working for Sydney's mother, but later proves to be an antagonist on his own. He has an instinct for self-preservation, thus making his loyalty flexible. During the third season he becomes the partner-in-crime of Vaughn's wife, Lauren, and eventually begins a relationship with her.
• Irina Derevko (Lena Olin) was a former Russian spy and is also the mother of Sydney. During the 1970s, she was sent to United States with the objective to seduce and marry Jack Bristow in order to steal information from him about a project he was working on. She also assassinated several CIA officers, including Vaughn's father.
• Lauren Reed (Melissa George) is a NSC liaison at the CIA, and marries Vaughn during the two-year gap between the second and third season. She is later revealed to be a mole sent by The Covenant to watch over Vaughn should Sydney contact him during her involvement with them and also to steal crucial information from the CIA.
• Nadia Santos (Mía Maestro) is Sydney's half-sister, and the daughter of Irina Derevko and Arvin Sloane. Introduced at the end of the third season, she is "The Passenger", a person who provides a direct line to Rambaldi. Prior to joining the CIA, she worked for the Argentine Intelligence.
• Rachel Gibson (Rachel Nichols) is a computer genius and introduced at the beginning of season five as an operative working for an organization that poses as the CIA known as The Shed. Unaware of this, she indirectly helps to apparently kill Michael Vaughn. After the truth is revealed to her, she joins the CIA in order to take down the organization that lied to her, much like Sydney did years before.
• Thomas Grace (Balthazar Getty) is an operative who is hired by Jack to join APO after the apparent death of Michael Vaughn. Years ago, his wife was shot and killed by an assassin who was intending to kill him.
• Renée Rienne (Élodie Bouchez) is an international terrorist known as "The Raven" who worked years with Vaughn in order to investigate a group of people known as Prophet Five. After Vaughn's assassination by the Prophet Five, she allies with Sydney to take down the group.
• Kelly Peyton (Amy Acker) is a friend and former colleague of Rachel's. She works for The Shed, and later directly for Prophet Five. Together with Derevko sisters, or maybe more, she is the most ruthless character of the show.