Marilyn Monroe, who had seen and loved Kim Stanley's performance in the Broadway production of "Bus Stop", patterned her accent on Stanley's, as well as those accents she had heard during her own time in the South. Monroe worked diligently on the hillbilly twang, speaking quite differently than in her other movies, and subverted her natural singing talent to make it painfully clear that Chérie was not gifted in that department.
Don Murray has said that Marilyn Monroe was actually naked under her sheets because she thought that her character would really have been naked.
Marilyn Monroe played Cherie, a role that Kim Stanley originated on Broadway. Some critics pointed out that Monroe's performance was an inflection-for-inflection recreation of Stanley's. Two years later, Stanley played a thinly-veiled version of Monroe in The Goddess (1958).
Don Murray suffered painful facial cuts when Marilyn Monroe overdid a scene in which she had to slap him with the sequined tail of her costume.
Despite her dedication and determination, Marilyn Monroe remained hampered by her insecurities once the camera started rolling. Some of this she was able to channel creatively into the character's own confusion and uncertainty; at other times she had great difficulty in simply getting through a scene and remembering the lines.