* ActingForTwo: TheMusical originally had Fred Applegate play both Inspector Kemp and Harold, the blind Hermit.
* AFIS100YearsSeries:
** AFIS100Years100Laughs: #13
** AFIS100Years100Songs:
** #89, "Puttin' On The Ritz"
* BillingDisplacement: Teri Garr, who portrays Inga, is billed below Madeline Kahn (Elizabeth) and Cloris Leachman (Frau Blücher), despite being the female lead and having more screentime.
* CreatorCameo: The howling wolf sound on the ride to the castle was made by Creator/MelBrooks. He also voices the cat Frankenstein hits with a dart and the original Dr. Frankenstein.
* DeletedRole: Leon Askin played a lawyer (reading the last will) but was cut out.
* FakeNationality: In ascending order: Inga, Frau Blücher ([[RunningGag *WHINNY*!]]) and Inspector Kemp.
* PlayingAgainstType: Creator/GeneHackman appears in a rare comedic role.
* RecycledSet: A lot of the laboratory equipment were Kenneth Strickfadens original props from the ''Film/{{Frankenstein 1931}}''.
* ThrowItIn
** Igor's hump, which changes position from scene to scene; Marty Feldman decided to do this on his own, without telling anybody beforehand. When someone finally noticed, they added a bit where Frederick does as well.
*** This has appeared again in other Creator/MelBrooks films - Prince John does it with his facial mole in ''Film/RobinHoodMenInTights''.
** During a search in the forest, Inspector Kemp's wooden arm appears to have switched sides. On closer inspection, it's actually the entire scene that's obviously been flipped as his eyepatch and monocle are on the other eye, and his badge is on the other side.
** Creator/MelBrooks ad-libbed the sound of a cat getting hit with one of Frederick's darts.
** Almost a Throw It ''Out'' moment; in some interviews, Brooks stated that the only point during production where he and co-writer Creator/GeneWilder seriously disagreed was the inclusion of the "Puttin' On the Ritz" number. Gene loved the idea but Mel hated it. After Gene vehemently defended the scene, Mel decided, "If you feel that strongly about it, we'll shoot the scene. If it works, we'll use it, if not, we won't." They shot it and it became one of the highlights of the movie.
*** The monster's shout of "PUTTINAHNDARIZZZ!" was Peter Boyle's idea.
*** Wilder wrote in his autobiography that he kept trying to find ways to add additional scenes to the shooting schedule because the cast had a thoroughly great time together and Wilder didn't want filming to end.
** "Soitenly! You take the blond, I'll take the one in the toiban!" Marty Feldman's Creator/GrouchoMarx-esque riff was one of many moments that Mel Brooks was not expecting, to his delight.
** The blind man's parting line "I was going to make espresso!" was improvised by Creator/GeneHackman. The scene ''immediately'' fades to black to cover up the laughter of the film crew.
* {{Tuckerisation}}:
** The Gasthaus, or guest house at the beginning of the riot scene is Gasthaus Gruskoff, named after producer Michael Gruskoff.
** The name on the third brain when Igor makes his selection is that of the movie's assistant property master, Charles Sertin.
* WhatCouldHaveBeen: Originally in the script, after Igor drops the brain jar, he was to turn to the camera and quip, "Funny thing is, I tried!"

* The Music/{{Aerosmith}} song 'Walk This Way' is named after Igor's cane gag.

!! This film [[ImageSource provides the page image]] for:
* CreatorKiller
* CreepyHousekeeper (WHINNY!)
* FictionalDocument
* FishEyes
* RollInTheHay
* TheVonTropeFamily