Trivia: In the waiting room of the dentist office, you can see a Buzz Lightyear action figure lying on the floor.

Continuity: Before Nemo is initiated into the Tank Gang, Brother Bloat introduces the Ring of Fire. Bloat then retreats and goes between the on-looking fish. In the next shot Bloat is on the outside/right. In the following shot Bloat is again in the middle.

Deliberate "mistake": When Dory is inside the whale, she doesn't have the scars from the jellyfish sting anymore. [This is actually a long-standing Disney tradition. The company seems to believe that it is less traumatic to see violence onscreen if the evidence is gone immediately (blood, scars, etc. always disappear). Still an error, but it wasn't the fault of the CGI animators.]

Continuity: The "'For a bite that counts', alligator floss'" poster on the wall, next to the window, disappears as the dentist grabs the pelican, then it suddenly reappears. The poster is first visible in an earlier shot.

Factual error: Near the end of the movie, when the fish are inside bags and have crossed the street and into the water, you can see the water level in the bags is much higher than the water they are sitting in. In reality, the water level inside the bag would have closely matched that of the surrounding water.

Continuity: When the dentist wants to put Nemo in a bag, he has a Ziploc (a plastic bag with a zipper) but when he finally catches him, it has changed to a normal plastic bag.

Continuity: When Marlin and Coral check on the eggs in the nest, when they first look, no eggs can be seen at the mouth of the cave but a couple of shots later the eggs appear.

Continuity: As the fishing net is being pulled up, a fisherman is shown to the left of two wires on the boat leaning on his elbow. Then in the very next shot, the fisherman is in between the two wires, and now he is leaning on his hand.