Though the music at the pub comes from a coin-operated player piano, it, along with everyone talking in the pub, stops short at the startling arrival of the Invisible Man.
Griffin says he must conceal himself for an hour after eating, as the undigested food is still visible. He also says he can be seen in a mist or fog. By that logic, we should be able to see the cigarette smoke in his lungs while he is smoking. But it is not visible.
When Griffin first visits Kemp, he locks the library door and puts the key in his pocket, but when Kemp leaves at the end of the scene, he easily opens the door which is now unlocked.
When Dr. Kemp stands before Dr. Griffin's opened cupboard, his cigarette jumps from his left hand to his right between camera cuts when Dr. Cranley walks away.
Crew or equipment visible
During the riot at the pub, a technician can be heard yelling, "Stay on camera!"
Errors in geography
A British Police station has the American words 'Police Department' spelled out on the door.
The pub in Iping has an American-style dartboard instead of the more elaborate British-style dartboard.
The film appears to be set in England; however, the train that gets wrecked has a distinctly American appearance.
The men at the Lion's Head Inn are throwing darts from a 45º angle left of the dartboard, yet the darts in the board are from straight-on shots.
The action of the film takes part during the British winter months, yet when the crowd are gathered outside the public house discussing the stranger a fly is clearly visible in shot.
When the Invisible Man is riding away on the stolen bicycle, a practice mark and/or track can be clearly seen on the ground in front of the bike; the tires of the bicycle follow it perfectly.
When the Invisible Man is in his pajamas and getting ready for bed, parts of his collar appear and disappear as his 'invisible' chin passes in front of it.
Wires are frequently visible moving objects that are meant to be moved by the Invisible Man. This is most noticeable when he rides the stolen bike.