Deliberate mistake: Rosemary believes that her baby is alive and proceeds to the closet that connects her apartment with the Castevet's and it takes well over a minute, and a bit of noise for her to undo the shelves. Dr. Sapirstein and Guy would have had to do the exact same thing when they broke into the apartment in the previous scene but it took them less than thirty seconds including the time it took to get into the Castevet's apartment from the hallway. (02:05:35)
Continuity mistake: When Rosemary has decided to sneak over to the Castevet's, she removes the towels from the closet shelves. She then tries to shut the door by pushing the towels (on the floor) into the closet. We see that the closet door does NOT shut all the way. Rosemary goes to get a knife, when she gets back to the closet, the door is completely shut, and she must now turn the knob to open it. (02:06:45 - 02:07:35)
Continuity mistake: Rosemary goes to the kitchen and gets a knife out of the holder with the remaining knives visibly crooked. In the next shot as she walks out of the kitchen they are straightened out. (02:06:50)
Visible crew/equipment: Rosemary walks into the party in the Castevet's apartment where she first sees the baby and you can see the shadows of a ton of stage lights and equipment on her shoulders. (02:08:40)
Continuity mistake: Rosemary walks into the party holding a knife and we see Guy talking to Minnie who is sitting next to a table full of gifts. Next time we see the table two shots later the gifts have been moved without anyone going near them. (02:08:45)
Continuity mistake: After she sees the baby, Roman says to Rosemary, "His power is stronger than strongerÂ…" and the clock on the back wall reads 8:20. Two shots later we see Laura-Louise's wrist watch and it reads 6:07. (02:10:55)
Continuity mistake: Minnie gives Rosemary a cup of Lipton's tea as she sits in a chair in front of a book case. We first saw these books when Rosemary sat down and they were all vertical, but then when she gets the cup of tea the books in both shelves are slanting to the left. (02:11:20 - 02:13:20)
Visible crew/equipment: At the end of the movie, Minnie gives Rosemary a cup of Lipton's tea as she sits in a chair in front of a book case and we see the camera shadow on the lamp on Rosemary's left. (02:13:20)
Character mistake: After Rosemary has the baby and they tell her it died, she calls them liars. They give her an injection and she passes out. When Guy comes back, he says that the Doctor says she was suffering from prepartum (not an actual word) symptoms. It would actually be postpartum.
Suggested correction: Actually, it depends on which time her 'crazies' were from. If Guy was referring to how she acted while still pregnant, then pre-partum would be correct. If referring to her tantrums after the birth, then it would be post-partum.
The post starts. " After Rosemary has the baby...".
Factual error: One of the Cadillac limousines during the funeral scene is from 1967, but the movie is supposed to take place between 1965 and 1966.