The award banquet Fletch interrupts is in honor of Fred Dorfman. Fred Dorfman the name of Kent "Flounder" Dorfman's brother in Animal House, which was originally going to feature Chevy Chase as Eric "Otter" Stratton. Otter was eventually played by Tim Matheson, who also appears in this movie as Alan Stanwyk.
When Mr. Underhill comes to collect the money for his lunch bill, Fletch searches for the time on his non watch-wearing wrist. This is a trademark of Chevy Chase.
Harold Faltermeyer replaced Tom Scott as the film's composer. However, Scott's name is visible on the early poster releases for the movie as well as the trailer included on the DVD.
Fletch tells beach drifter in one scene that he "feels like a hundred dollars". This line is also said by Ty Webb in Caddyshack, a role also played by Chevy Chase.
Irwin Fletcher's daydream of playing in the NBA was based partly on another "Earvin"; former L.A. Laker Magic Johnson. In the movie's promotional poster, Fletch's team ID card bears the name "Magic Christian" (a reference to The Magic Christian, a 1969 Peter Sellers movie based on a Terry Southern novel).
When Fletch tells Frank that he is quitting, he says that he's going to try out for the Lakers, because, according to Fletch, "they need a good power forward". In 1985, the Lakers' Power Forward was Mitch Kupchak, who would go on to become the General Manager of the Lakers.