According to interviews, Patricia Quinn only took a role in the play because she loved the opening song "Science Fiction - Double Feature". She was upset when she didn't get to sing the song in this movie, but agreed to lip-sync the words as the pair of red lips in the beginning, with vocals by Richard O'Brien.
When this movie first opened, it had a traditional release, with afternoon and early evening screenings. It bombed. Meat Loaf said he attended an opening week performance with writer and director Jim Sharman in the Midwest, and the theater was empty except for them. Midnight screenings became popular in the mid-1970s, and word of mouth began to spread that the midnight audience might enjoy this movie. It began showing at midnight in a few cities, and became so popular that it has been shown continuously in movie theaters since 1975, making it the longest theatrical run in history. The Museum Lichtspiele cinema in Munich, Germany has screened the movie every week since June 24, 1977, offering special "RHPS-Kits" to enable celebrations during the show. The kits contain a biscuit (for the toast), rice, a whistle, a candle (for "There's a Light"), and a sheet of paper with instructions for the Time Warp.
In an interview with Terry Gross on her radio program "Fresh Air", Tim Curry said that he got to meet King Charles III and Princess Diana because she loved Curry in this movie. She requested the meeting while he was in a production of "Love for Love" that they attended. Curry recalled that he was placed at the end of the receiving line, and while Prince Charles only vaguely recognized Curry from seeing him "on television", Princess Diana told Curry, with a "wicked smile", that Rocky Horror had "quite completed my education."
When Barry Bostwick pounds his fist on the table during the dinner scene he accidentally pounded on the hand of Susan Sarandon. The reaction from Sarandon is prominent and real. She got her revenge by (accidentally) stepping on Bostwick's foot with her spike heel during the Floor Show scene. His reaction is also visible.