Continuity: Season 6 - Episode 1 - My Mirror Image: Dr. Cox's hair colour and length change back and forth significantly during the episode.

Continuity: Season 5 - Episode 9: My Half-Acre: When JD and Julie have had their old couple photograph, JD takes his mask off and his hair is flat. In the next shot, it is waxed up and styled again.

Plot hole: Season 5, episode 20 (My Lunch). One of Dr. Cox' patients needs a heart valve transplanted. Heart valves don't have to be transplanted from another person. They can be replaced by a metal valve, or the surgeon can create a new valve from a different part of the patient's body. There was no reason to wait for a donor valve when they had other options available.

Continuity: The woman in the wheelchair that Dr. Cox claims is dead is wearing glasses in some shots but not in others.

Continuity: Right at the end, the shot shows Carla walking towards JD with a security guard in the background, the shot cuts to behind JD and suddenly the security guard has moved forward in position dramatically.

Continuity: When Elliot and J.D are going up the stairs and J.D asks if they are racing, Elliot has a watch on her left hand, then in the next shot when they are racing, the watch is gone and doesn't reappear.

Continuity: Dr. Cox's stethoscope is hanging down more on his left side, but when he walks around to J.D. it is now hanging evenly around his neck.

Continuity: When JD says it might be a penny blocking the door the Janitor says "If it's a penny in there, I'm taking you down" while placing his screwdriver on JD's shoulder. When it cuts he places it under JD's chin.

Continuity: When JD is in the lift (elevator) with all the people and asks his patient if his gas is bad for the other people, the woman on the right has her arms crossed then in the next shot she has a single hand on her chest.

Continuity: In the apartment there is a cardboard box on a table, with a strip of blue tape on it and a tube of paper sticking out of it. A few shots later another strip of blue tape suddenly appears on the box and the tube of paper has vanished.

Continuity: During JD's lunch with Turk and Todd his chocolate milk moves from his tray to the table between the closeup shots.

Visible crew/equipment: When Elliot turns to the lady sitting in the chair and says "so, when's the baby due?" a large green tape marker is blatantly visible on the floor behind her.

Continuity: When Elliot enters the guys apartment, she is startled by the dog, and she then walks in, leaving the door wide open. When J.D. goes to pick up the dog the door is now shut.

Continuity: When Dr Cox is watching TV, a guy in green walks past the people in the background, the camera goes to a close up of the doctor with the remote and the same guy walks past again.

Continuity: In the apartment, when they decide to watch "Fletch", there is a yellow cushion under J.D.'s right arm, sitting on the sofa. But it disappears between shots.

Visible crew/equipment: In the scene where JD and Elliot are treating a patient and JD says "It's the closest thing I had to a date recently" the microphone pops into screen from above at least two times.

Audio problem: When Dr. Cox is yelling at Dr. Reed and he's saying, "For the love of Aisha," he's mouthing the word God, but "Aisha" which was dubbed over.

Visible crew/equipment: When Dr. Kelso sits on the edge of a bed smoking a pipe, he says "right you are, sweetheart" and you can see a boom mic pop into view, above his head.

Continuity: When Dr.Cox is Talking to Elliot before she leaves the room her name tag flips over and back again.

Continuity: Dr. Cox throws his white coat on the table and sits down, when he starts talking to Elliot the coat is now missing from the table.