Actress Jodie Foster was offered the Princess Leia role in Star Wars: Episode IV - Eine neue Hoffnung (1977) around the time that this movie was in development when George Lucas had wanted to make the character young and Foster had actually got the part when it was realized that Foster was still under contract to Disney. There may have been a way for Foster to get out of the contract but her mother decided to honor the contract and as such Foster contractually completed Ein ganz verrückter Freitag (1976) for Disney in 1976.
Jodie Foster said of the film whilst doing press publicity for the picture around the time the movie first launched: "I think it's important for my career that I make all different kinds of films. I'm proud that I made Ein ganz verrückter Freitag (1976). I shouldn't make one kind of picture like so many child stars of the past did. And I thought the idea of Ein ganz verrückter Freitag (1976) was terrific. A lot of my friends think it's my best picture. I really like working for Disney."
Marc McClure (Boris Harris) would later play Boris the parcel delivery man in the remake Freaky Friday - Ein voll verrückter Freitag (2003). He is the only actor to appear in both films. He also played Jimmy Olsen in the Superman franchise and Dave McFly in the Back to the Future franchise.
Both Jodie Foster and Barbara Harris were nominated for Best Actress - Musical or Comedy at the 1977 Golden Globes for this film. Technically, as they also played each other's characters, they were both nominated for playing the same character(s).