Factual error: While Fletch is riding with the bikers, they stop at a stop sign where a family in a station wagon roll up their windows in fear. A sign at a service center in the background is the Castaic Junction, which is in the greater Los Angeles area. The movie is supposed to be taking place in Mississippi and the deep south.

Continuity: When Fletch goes to visit Calculus in his shack, he knocks on the window and sees Calculus sitting in a chair and wearing boots. The next shot has Fletch walking inside and Calculus is now wearing socks and no boots despite never having left the seated position.

Continuity: In the scene where Fletch goes into the Biker Bar it's pouring rain. When he comes out minutes later and goes riding on a cycle its not raining and the ground is completely dry.