It received an X rating in 1968, but was downgraded to an R in 1972. Director Robert Aldrich spent $75,000 unsuccessfully battling the X rating in court.
The original Broadway production of "The Killing of Sister George" by Frank Marcus opened at the Belasco Theater in New York on October 5, 1966, ran for 205 performances and was nominated for the 1967 Tony Award for the Best Play. Beryl Reid won the 1967 Tony Award for Best Actress in a Play and recreated her role in the movie version.
The lesbian lovemaking scene so disgusted Robert Aldrich's longtime composer friend Frank De Vol that he quit the production and didn't work with Aldrich for several years.