To help build up Judy Holliday's image, particularly in the eyes of Columbia Pictures chief Harry Cohn, Katharine Hepburn deliberately leaked stories to the gossip columns suggesting that her performance in Adam's Rib (1949) was so good that it had stolen the spotlight from Hepburn and Spencer Tracy. This got Cohn's attention and Holliday won the part in Born Yesterday (1950).
Judy Holliday and Broderick Crawford extended their famous gin-rummy scene to their off-screen relationship. Afraid of flying, Holliday insisted on taking the train to Washington for location shooting. Crawford went along and they passed the four-day trip playing gin for money. When they arrived in Washington, Holliday had won $600 from him, along with his undying friendship.
William Holden and Broderick Crawford became good friends during filming, united by their fondness for liquor and a mutual dislike of Harry Cohn. Among the jokes they played on him were ordering large Scotches at lunch so he would worry about their getting drunk in the middle of a shooting day. They also ran up huge bills for room service during location shooting in Washington just to aggravate him.
Costume designer Jean Louis gave Judy Holliday 13 outfits that became more stylish and tasteful as her character grew in knowledge and self-awareness.
In his autobiography, Garson Kanin wrote that Harry Cohn paid the record $1 million for the film's rights because he had heard that Kanin said he "wouldn't sell the rights to Harry Cohn for any amount - not even a million dollars."