1.Warner Bros. was initially concerned and hesitant about the casting of Phoebe Cates as Kate, due to her being primarily known for her risqué role in Fast Times at Ridgemont High.
2.Emilio Estevez was considered for the role of Billy.
3.Gremlins was originally planned and scheduled for a Christmas-season release, but the film was rushed into production after Warner Bros. learned it would have no major competition for the summer movie season.
4.Originally Gizmo was supposed to be the villain, turning into a Gremlin himself and becoming the leader of the Gremlin pack.
5.In the original version of the script, the Gremlins kill both the family dog and Billy’s mom by cutting off her head and tossing it down the stairs.
6.Gremlins and Indiana Jones and the Temple of Doom are credited as the films that lead to the creation of the PG-13 rating.
7.In the first scene of the movie, Mr. Peltzer walks in front of a broken-down AMC Gremlin.
8.The set for Kingston Falls is the same one used for Hill Valley in Back to the Future.
9.The movies listed on the marquee: A Boy's Life (the working title for E.T. the Extra-Terrestrial) and Watch the Skies (the working title for Close Encounters of the Third Kind).
10.Gizmo never eats in the movie.
11.Mr. Hanson, the science teacher, was originally killed by dozens of hypodermic needles to the face.
12.There is a cameo by Chuck Jones, the legendary animator for Looney Tunes.
13.This was the first film to use the now familiar Amblin Entertainment logo.
14.Gizmo was voiced by Howie Mandel.
15.Stripe is voiced by veteran voice actor Frank Welker, best known as the voice of Fred on Scooby-Doo, Where Are You!
16.If you look closely, you'll notice that Stripe is the only Gremlin who didn't sing at the movie theater.
17.While watching Snow White and the Seven Dwarfs, one Gremlin is wearing Mickey Mouse ears.
18.The scene at the end where Stripe hides from Billy in a pile of stuffed animals is a reference to the scene in E.T. (as a gag, an E.T. doll is shown in the shot).
19.Stripe is the only Gremlin in the film to die by sunlight.
20.The WWII-era Looney Tunes cartoon Falling Hare (where Bugs Bunny is harassed by a gremlin) was supposed to show before the movie.