The school desks had to be raised so that some of the girls wouldn't look as grown-up as they really were. In fact, one of the girls was a 21-year-old mother.
Seventy-five girls were needed for this movie, and about 500 showed when auditions were held in London. Faced with such an overwhelming number, the director's assistant separated the girls into more manageable groups of 20. Director Ronald Neame then asked each girl to giggle, and he made his selections based on how well the girls could do so.
The original play was offered to Dame Maggie Smith first. Because of movie commitments, she declined and Dame Vanessa Redgrave played Miss Brodie on stage. However, when this movie was being made, the role of Miss Brodie was offered to Redgrave first. This time, she had prior commitments and declined and Dame Maggie Smith took the role, offered her originally, and won an Oscar for playing it. According to director Ronald Neame, Redgrave phoned him saying that she refused to repeat that "proto-Fascist part." Neame claims he was relieved because he didn't want to use her anyway.
Dame Maggie Smith and Sir Robert Stephens were married to each other during filming. The cast included two pairs of married actors: Maggie Smith and Robert Stephens, and Gordon Jackson and Rona Anderson.
Originally released March 1969 in the U.S., it was re-released after Dame Maggie Smith won the Academy Award for Best Actress in April 1970 and brought the studio an additional $1.9 million.