This is the only film in which Carol Haney had a speaking part. In all her other films she was strictly a dancer.
39% of the cast is from the original Broadway production.
One of the main problems in the factory is that the workers want a 7-1/2 cent raise and are willing to go on strike to get it. Nowadays this doesn't seem like much, but the average mill/garment worker in 1954 (when the play was written) made on average about $1.25 an hour, or about $50 a week. The raise would add $3.00 to each paycheck, so the 7-1/2 cents would be about a 6% increase.
In her autobiography, Doris Day recounted how, as one of only four cast members who hadn't appeared in the Broadway production, it was challenging to fall into the groove of a company that had been playing the show for more than one thousand performances together. She described the experience as trying to find her place in a well-oiled machine.
Jack Warner optioned the film rights to both The Pajama Game (1957) and Damn Yankees (1958) with the idea of teaming stage director George Abbott and film director Stanley Donen to ensure both a faithful transfer and a cinematic rendition of the original shows. In each case, Warner was willing to import the entire original cast for the film version as long as one of the leading roles was played by a bankable movie star. For The Pajama Game (1957), the initial plan was to cast Frank Sinatra as Sid, pairing him with Janis Paige, who played Babe on Broadway. When Sinatra turned down the role, Warners decided to retain John Raitt from the stage version, playing opposite the studio's resident nightingale, Doris Day. This move cost Paige the movie, but she bounced back quickly, securing a showy role in MGM's film version of Silk Stockings (1957), which she effectively stole out from under Fred Astaire and Cyd Charisse.