The dog in the movie, Rommy, was trained in the Weatherwax kennels, most famously known for making an undisciplined collie named "Pal" into a star named Lassie the Dog. The Weatherwax family readily admitted that of all the dogs they trained, Rommy was their favorite, and was the smartest of their dogs.
In order to create the dilapidated farmhouse, the house used in Arsenic and Old Lace (1944) (filmed in 1941) was modified by knocking out banisters, rafters and plaster, winning an Oscar® nomination for their creative demolition. For George Washington Slept Here (1942), Max Parker, Mark-Lee Kirk and Casey Roberts were nominated for Best Art Direction-Interior Decoration in a Black-and-White film.
In the play, it is Bill who buys the house and Connie who's frustrated by the expenses. The movie swaps their characterizations in order to bring it in line with Jack Benny's established miser persona.
After seeing the play on Broadway, Jack Benny insisted that Percy Kilbride should reprise his role as the handyman, Mr. Kimber, in the film version. Benny managed to convince studio head Jack L. Warner to bring Kilbride out to Hollywood for a screen test, even though Warner thought there were plenty of local character actors who could take the handyman role. However, once filming began, Benny and his co-star, Ann Sheridan found they could barely get through a scene with Kilbride without laughing. Warned by director William Keighley that constant re-takes were taking the film over-budget, Benny finally had to resort to not sleeping at night, so that when he came to work in the morning, he would be too tired to laugh at Kilbride's character.
Jack Benny's character mentions The Phil Harris Orchestra, in the movie. This orchestra was Mr. Benny's Band on The Jell-o Show starring Jack Benny in 1936, later changed to The Jack Benny Show.