Goofs

When Fleming finds the floor plans and The Bat attacks him, the paper of the plans appears to be black, but when The Bat is carrying it after the murder, it's white.

Toward the end of the film, Davenport makes a call to the police department; however, that phone call could not have gone through since the phone line had been cut clean through using wire cutters earlier that evening. Cornelia verified this after trying to make a call by declaring that the phone lines were dead.

The Bat uses a suction cup and a glass cutter to cut a hole in the glass in order to reach in and unlatch the door. The circular piece of glass attached to the suction cup is twice as thick as the glass from which the hole has been cut. The glass attached to the suction cup is also too thick to cut a hole in using a simple glass cutter.

This is a common movie cliché that has no basis in reality, as glass cannot be scored deeply enough to pull out a circle with just a suction cup. Instead, the glass must be also scored along multiple diameters, then tapped with an impact load, such as a mallet, with just the correct force in order to push out the disc. The whole process would take far longer than what is depicted in movies.

Obvious stunt double for Vincent Price when the fight with The Bat ensues in doctor's lab.

When Dr. Wells is in the lab handling a bat, a ringing sound is heard through the receiver while it is off the hook (operator calling). It would not be possible for a recipient to be reached via a phone call when the receiver is already off the hook.

Dr. Malcolm Wells' first name is misspelled as "MALCOM" on his wrought-iron front gate.

Warner explains that he fixed a leak by "packing the elbow". To fix a leak, you pack a faucet or a valve, not an elbow.