Continuity mistake: In the final destruction-of-the-temple scene, the huge statue of Dagon starts to topple head first, but in later shots it is sliding towards the camera feet first. This is because director Cecil DeMille was not satisfied with the first take and had the temple re-erected then collapsed a second time. Shots from both destructions are spliced together in an exciting sequence, but rather puzzling architectually.
Continuity mistake: In the scene where Mary is eating her oatmeal while Martha is talking to her, take a look at Martha. While talking to Mary she spits out a piece of bread she was eating and this causes the little girl who plays Mary to momentarily slip out of character and smile (almost ready to laugh).