Mr. Stine makes the comment that he has sold more books than author Stephen King. Surprisingly, this line of the film is true. King having sold over 350 million books and R.L. Stine having sold over 400 million books.
The real R.L. Stine commended the filmmakers for allowing him to read the script and make suggestions.
The alias "Mr. Shivers" that R.L. Stine uses before revealing himself is a reference to the Shivers books, a series of horror-themed children's novels that were released in 1996, near the end of the original Goosebumps run. The Shivers books were considered by many to be a shameless rip-off of the Goosebumps series, and Stine's use of "Shivers" as a false name is a tongue-in-cheek reference to this.
R.L. Stine observed that one of the major hurdles in getting a Goosebumps movie made was having too many books to choose for adaptation, and that it was a masterstroke of this film to include all of the characters in an original story.
Tim Burton was originally to produce the film in 1998, and was attached to it, but the project fell through.
R.L. Stine: The real Stine makes a cameo and says hi to Jack Black while walking through the halls of the school at the end of the movie. The real R.L. Stine's character name was Mr. Black and Jack Black was Mr. Stine.