The Secret of NIMH is a 1982 American animated fantasy adventure drama film directed by Don Bluth in his directorial debut. It is an adaptation of Robert C. O'Brien's 1971 children's novel Mrs. Frisby and the Rats of NIMH. The film was produced by Aurora Pictures and released by United Artists. The film features the voices of Elizabeth Hartman, Dom DeLuise, Arthur Malet, Derek Jacobi, Hermione Baddeley, John Carradine, Peter Strauss, and Paul Shenar. The "Mrs. Frisby" name in the novel had to be changed to "Mrs. Brisby" during production due to trademark concerns with Frisbee discs. It is the sixth animated feature film to be presented in the Dolby Stereo sound system. Released to wide critical acclaim, the film was a moderate commercial success. It was followed in 1998 by a direct-to-video sequel called The Secret of NIMH 2: Timmy to the Rescue, which was made without Bluth's input or consent.