Don Francks, who voiced Dr. Claw in several season one episodes, asked the producers if his daughter, Cree Summer, could audition for Penny. It became her first acting role.
Dr. Claw's face was never shown throughout the entire run of the show, though his cartoon face was finally revealed via his action figure release.
The first animated TV show with stereo sound.
The show contains references to Don Adams's previous series Get Smart (1965):
- The basic plot of an inept agent going up against a malevolent criminal agency with anonymous help from his close friends
- The opening sequence has Gadget going through many doors to meet Chief Quimby, which Smart did in Get Smart (1965)'s opening sequence
- Don Adams reused some "Get Smart" catchphrases for Gadget's character. These included "Would you believe...?" and "Sorry about that, Chief."
- The series main antagonist is 'Dr. Claw', while "Get Smart" had a villain (in two episodes) named 'The Claw'.
When production moved from Toronto to Los Angeles, the Canadian voice actors were replaced with US voice actors. Holly Berger replaced Cree Summer, and Maurice LaMarche replaced Dan Hennessey.