Deliberate "mistake": When Tiffany calls Ruth Bailey, you can see that the mobile phone she uses is turned off.

Factual error: Joan should have still heard Jennifer screaming when Tiffany hung up on her extension, The line would not have been disconnected because Jennifer's extension was still off the hook.

Audio problem: When Glen/Glenda is in the baby cradle, the words do not match the lips when he/she says, "We can finally be a real family."

Continuity: Towards the end when Glen cut his father's arm off, you see him lying there screaming and bleeding. The blood from his arm on the floor is making a puddle and then it cuts to Glen's face. When it shows Chucky's arm (or stump) again, there is no puddle, just blood following the crack in the floor tile.

Continuity: During the Sound Stage scene, Chucky and Tiffany kill the puppeteer by chopping his head off with wire. When the blood splatters all over Tiffany's and Chucky's faces, Tiffany's right eye is covered in blood. In the next shot there is no sign of blood in the eye at all.

Continuity: When Jennifer is getting ready for her date, the perfume is on the table in the first shot, but in the next shot, she is spraying it on herself.

Visible crew/equipment: When Redman arrives at Jennifer Tilly's house, in the front of his car you can see a camera operator. (Time)

Visible crew/equipment: When Jennifer Tilly is being hassled by the paparazzi, she gets in the front of the car, then the camera follows Chucky, Tiffany and Glen's feet hopping in the car. Watch the silver limo bar, the camera dolly track is visible in it. It can't be the limo's feet reflection, because the camera reflection moves and stops the exact same time as the camera stops in its tracks.

Visible crew/equipment: In the scene where the box containing Glen/Glenda is in the SFX room, as Glen/Glenda crawls out of the box, a shadow of the boom mic and the pole is very apparent on the wall behind the box.

Audio problem: Joan is already screaming when Glenda burns her, but the scream effect doesn't kick in until a second afterward.

Factual error: When the babies are born, there are no umbilical cords.

Deliberate "mistake": When Jennifer is being pursued by Tiffany in her house, Jennifer trips over her stiletto. When she falls you can tell it is a stunt woman as she is a bit shorter than Jennifer Tilly (also look at the ass). Revealed in DVD commentary.

Visible crew/equipment: After seeing Frankenstein, Wolfman and a melted figure, Glenn walks by two set of shelves. On the second one, as he walks by, you see the gnome's reflection then the camera's reflection in a drawer.

Visible crew/equipment: At the start, when Glen/Glenda kills the girl's parents then wets himself, you can see the reflection of the camera in the puddle.

Deliberate "mistake": When Joan is burned and she flies over the railing, you see it's not Joan but a stunt double. The stunt double is also obvious in other shots in the film.