As Barnabas and Julia look through the bars of the basement door, Barnabas believes the camera to have left them at a certain moment. Thinking that no one is watching, he mutters something to Julia and sticks a finger up his nostril.
Tom Gorman as Mr. Prescott accidently refers to Victoria as 'Gloria Winters'.
In the closing credits, Thayer David walks in and sees the camera and walks out.
When Dr. Lang leaves a message on the tape recorder, the actor accidently turns off the machine.
The flame in Cassandra's cigarette lighter, which she is using to hypnotize Tony Peterson, goes out. This forces her to restart the flame.
A big blooper! As Bathia Mapes attempts to exorcise Barnabas, the actress (Anita Bolster) forgets her line all-of-a-sudden and there is a long pause. After several seconds go by, producer Robert Costello can be heard off-camera yelling out her next line. Bathia then proceeds...
Nathan Forbes' jacket becomes entagled when he enters Collinwood.
The first time Peter (Roger Davis) mentions Nathan, he calls him Lt. Collins-but then quickly says Forbes.
A crew member can be seen when Barnabas confronts Angelique in the secret room of the mausoleum.