Continuity mistake: Near the end of the film, Karl Malden is embracing Vivien Leigh. In one shot she has her left forearm against his chest, with her hand in the vicinity of his shoulder. In the next shot this arm is instantly around his neck.
Continuity mistake: When Stanley throws the radio out of the window, he throws it through the second pane of the right hand side, but when the camera comes back to it, it is now the left hand pane that is smashed.
Character mistake: At the poker game when Stella and Blanche come back from their movie, Stella is near the wall with her back towards Marlon Brando. As she says her line "how much longer is this game going to continue?", you notice Marlon Brando also says that line to himself as if he memorized the screenplay.he responds "Until we get ready to quit" and slaps her butt. (00:31:15)
Deliberate mistake: Before Blanche's birthday dinner, she comes out of the bathroom with her wet hair up in a towel and asks Stella for another towel saying she's just washed it. Moments later she emerges from the bathroom with completely dry and styled hair that would have taken hours to do during that time period.
