Factual error: In the episode where Sydney is supposed to be in Helsinki, there are visible skyscrapers in the background. There are no skyscrapers in Helsinki.

Continuity: Emily Sloane's left ring finger was shipped to Arvin Sloane in one episode in Season 2, when they are reunited in the Philippines, the left ring finger is bandaged and missing. Later, in the episode when she is shot, when she tells Arvin the CIA is listening, the left ring finger is there.

Continuity: "Season premiere, Authorized Personnel Only, part 1." When Sydney and the other agent are in the bathroom at the club, Sydney begins to smear black dirt on the agent's tee shirt for his punk transformation. The first smears that she applied differ when he exits the bathroom.

Other: Season 4: Episode 3- "The Awful Truth" Near the end of the show they are supposed to be in a parking garage in Spain, but there are way too many American cars.

Continuity: In Season 3, Episode 11 "Full Disclosure", when Sydney is torching the lab you see 6 test tubes labelled with her name shatter and spill. In the next shot the tubes are back on the rack and intact.

Revealing: In episode 3x10, Remnants, when Lazare shows up to talk to Will, we see that his left hand has been cut off. When Lazare is about to leave, he has his hands at his sides, and we can see that both arms are the same length, but the left one should be shorter, because it has no hand.

Plot hole: "Unveiled", episode 3x18. Vaughan discovers Lauren is a mole when he goes through her briefcase and discovers the wig, gun and fake passport she used in Germany a few hours before - surely even the worst secret agent in the world would have enough sense to get rid of such incriminating evidence as soon as possible, and not carry it back to the USA (sneaking it onto a plane, presumably) and leaving it in the room where the man you're lying to sleeps. Lauren is a highly skilled agent, if the Covenant selected her for a mission this important, so it's out of character (without an explanation) for her to be so sloppy.

Other: For secret agents, Sydney and Dixon are not very dedicated to secret identities. At several points they refer to each other by their real names in front of other people while they are under aliases. Examples include The Confession party and The Coup Las Vegas scenes.

Revealing: When Syd's Dad rescues her in the car park, he starts shooting at the other car. After firing one shot the slide of his gun locks back (indicating it's out of bullets), but when the angle changes he carries on firing with no problems.

Continuity: When Sydney is tortured, she loses some teeth and a stream of blood flows out the right side of her mouth. When she returns to SD-6 and speaks with the director, the blood is gone (fair enough). Outside on the street in the following shot, the blood has returned, but there's no reason to believe that she is still bleeding.

Continuity: In the parking garage, after Sydney knocks the machine pistol out of the hit man's hands, it lands with the barrel pointing away from the two of them and remains in that position during their entire fight. When Sydney grabs it off the ground, the barrel is pointing toward them.

Continuity: After Sydney learns that SD-6 is not part of the CIA, she goes to Taipei. Just after she arrives, she takes a man's car. At this point the number plate reads DH 5578, but, in the next shot, as she is driving away, it is JU 1587.

Continuity: When Sydney and Danny are at the pumps outside the city talking about her job, between front and back shots the hair at Sydney's left ear changes position from stray strands blowing in the wind to neatly tied back - no stray strands.

Continuity: When Syd is talking to her moronic handler at the magazine stand, when he says "who do you think you're talking to?", shots of him show Syd facing straight ahead, but shots of her show that she's turned towards him.

Factual error: Jennifer is sent to Malaga, Spain, but right after the location pops on the screen it fades to the city hall in Stockholm, Sweden.

Continuity: As Anna approaches Syd in the middle of the field, she reaches her hands up to her belt. In the very next shot from behind her, her arms are by her sides.

Continuity: When Jack meets Vaughn in the restaurant he pours some liquid into his cup. On the front shot he picks the cup up before he pours, we then cut to a reverse angle and the cup is on the table.

Continuity: When Sloane is talking to Sydney towards the end, he slides some documents towards her. After that shot, when the shot's of Syd we can see that Sloane's holding his hands near his face, but in front shots of Sloane they're down by the desk.

Revealing: When Sydney and her father go into the office to talk, the office doors begin to close before Sydney uses the remote to close them.

Continuity: When Roger Moore is showing Sloane the bank accounts, he says "5 deposits in excess of $45 million...", but the shot just before that shows deposits of (in thousands), $9,362, $7,215, $9,010, $8,300, and $9,250. That makes $43,137,000, which isn't in excess of $45 million.