Continuity: In the beginning Professor Lindenbrook places his mountain goat horned ink well out of the way behind some scales, any other scene after that, they are missing.

Factual error: The Sun was shining quite brightly on the shores of the underground ocean (near the center of the Earth) as can be seen by the shadows of the actors.

Revealing: When the first dimitridon (the sail-finned dinosaurs) shows up, the dimitridon's face changes color from the wide shot and the closeup of it and the Professor and the Count because of bad matting effects.

Revealing: A boulder tumbles towards James Mason and his party though a cave. With all the smashing against the walls and floor of the cave, the boulder stays entirely intact. However, just before the boulder hits a wall with two tunnels while flying through the air, the boulder now shows two majors fractures that were unseen earlier. The fractures were added to the boulder to give it a more dramatic impact by it breaking up with one piece nearly striking James Mason.