Martin Mull and Lesley Ann Warren had previously worked together in the movie Clue (1985) as Colonel Mustard and Miss Scarlett, respectively.
David Gallagher and Jake Richardson also appeared in the 7th Heaven (1996) episode, Johnny Get Your Gun (1998), as Simon Camden (the series' regular) and Johnny (Dina's ex boyfriend), respectively.
Edward Herrman and Christine Ebersole were asked to reprise their roles as Richie's parents from the first film but both declined because they did not want to do the movie without Macaulay Culkin or Donald Petrie who directed the first film. Similarly Jonathan Hyde was not asked to reprise his role as Cadbury because he had just finished filming Titanic (1997) which became the highest grossing film in history at that time and he was deemed too expensive for this movie's small budget due to that films massive success, so Cadbury had to be recast with an actor more affordable.
Mike McShane who played Professor Keenbean in the first film was also asked to return for this sequel but he disliked the script as well as the change in casting and decided to appear in Office Space (1999) instead. He was replaced by Eugene Levy.