All episodes end with the word "ALIAS" appearing on the screen, except for the final episode of the final season in which the message "Thank you for five wonderful years" appears on screen instead.
Opening credits generally do not appear until after the first act, 10-15 minutes into the episode. This was an unusually late appearance for an American TV series, but it seems to have set a trend.
The fourth season opening credits are presented over rapidly intercut shots of all of Sydney Bristow's aliases prior to the fourth season.
The first few episodes of the first season do not have the "My name is Sydney Bristow..." introductory monologue; neither does the later season 1 episode "Q & A." By midway through the second season, the opening narration (which by that point was no longer recited by 'Jennifer Garner') was replaced altogether with a recap of previous episodes.
Beginning in the second season, episodes that are running too long have no opening theme. The credits are played over the episode and the only title logo you see is the black screen with the words ALIAS that is seen at the end of every episode.
According to creator 'Jeffrey Abrams', the background of the words "Alias" in the opening credits come from home movies of his family. Also in the opening credits, the "Rambaldi" symbol is visible for a split-second.
The opening credits feature J.J. Abrams' trademark lens flares.