The “Sisters” comedy act that Bing Crosby and Danny Kaye perform was not originally in the script. They were clowning around on the set and the director thought it was so funny that it was written in.

The original idea was to reunite Fred Astaire and Bing Crosby, as they had been successful in Holiday Inn. Astaire refused, as he had “retired” at the time, so the part was reworked for Donald O’Connor. O’Connor pulled out due to illness, and the part was reworked for Danny Kaye.