The script, written by Curt Siodmak, follows The Ghost of Frankenstein (1942) and The Wolf Man (1941), though with a number of retcons.

Four years after the events of The Wolf Man and The Ghost of Frankenstein, two graverobbers break into the Talbot family crypt during a full moon.

Larry is found by the police in Cardiff later that night, still with the head wound thought to have killed him, and taken to a hospital where he is treated by Dr. Mannering.

Using a stone, Larry breaks the ice and pulls the creature free, hoping he can show him Frankenstein's notes.

Vazec, the innkeeper, suspecting Elsa, Mannering, and Maleva of conspiring with Larry and the monster, destroys the dam overlooking the Frankenstein estate with dynamite, hoping to drown all five of them.

Elsa escapes from the castle with Mannering, but the Wolf Man and the monster, engaged in their fight, are both swept away in the flood.

Cast adapted from the book Universal Horrors:[1][3] Curt Siodmak discussed the development of Frankenstein Meets the Wolf Man at the beginning with producer George Waggner proposing the title to him.

[3] Richard G. Hubler of the Saturday Evening Post stated that the film was prompted by the nearly one million dollar gross of The Wolf Man (1941).

[3] Several minor changes were made to Siodmak's script before the film was completed, such as grave robbers finding Talbot's body with long fingernails, a hospital scene with Dr. Harley (later changed to Dr. Mannering in the film) and Inspector Owen finding Talbot's clothes rotten and moldy and his shirt falling apart.

[4] Frankenstein Meets the Wolf Man went into production in October 1942 with Waggner producing and Roy William Neill directing.

[3] The climactic battle between the Wolf Man and the monster was handled by two stuntmen, Gil Perkins for Lugosi and Eddie Parker.

[4] On October 5, 1942, Maria Ouspenskaya suffered an ankle injury, and Lugosi collapsed on set and was ordered home by a physician.

[7] Following a preview screening in the studio, the film played normally until Bela Lugosi as the monster spoke, upon which the staff on hand convulsed with laughter.

[8] Edward Bernds, the sound man on other Neill films stated that the director had "absolutely no sense of humor" and would not have recognized the comedic nature of the scenes.

"[6] Author and critic Kim Newman proclaimed the film to be "one of the most-often excerpted films in movie history", noting that it would later appear in the background of Mad Dog and Glory (1993), being ignored by Robert De Niro and Uma Thurman as they have sex, and appearing in the background of Alien vs.

[11] Kate Cameron of The New York Daily News gave the film two and a half stars, noting that the "producers have spent time and money on the production and have gone to considerable trouble to give it the proper atmospheric touches".

of Variety declared that Siodmak "delivers a good job of fantastic writing to weave the necessary thriller ingredients into the piece" and "director Roy William Neill deftly paces the film with both movement and suspense to keep audience interest on sustained plane".

[5] The authors criticized the screenplay by Siodmak as a weak element, noting how it either ignores or forgets events of the previous films.

[3] The authors of Universal Horrors declared that these films are "often blamed for the decline and demise of the classic Dracula and Frankenstein series, but by the mid-40s they were on their last legs anyways",[3] and the monster rallies "may be juvenilia, but they're slick and enjoyable, and a welcome opportunity for many of the best-loved horror stars to congregate in a single picture", and that among these monster rallies, Frankenstein Meets the Wolf Man was the best in the series.