For this film, "Dynamation"--the name of Ray Harryhausen's stop-motion effects technique--was rebranded "Super-Dynamation". Only one other Harryhausen film has this brand: his subsequent film, L'Île mystérieuse (1961).
The film takes place in 1699.
As of this film's production, both Ray Harryhausen (the creator of special visual effects) and producer Charles H. Schneer decided to make their permanent homes in London. This was not only because of Harryhausen's love for the exotic European locales he would use in all of his future projects, but it was also cheaper to make his kind of movies there. Harryhausen lived in London ever after, whereas Schneer lived there for 45 years before moving to Florida in 2005, four years before his own passing.
The music for "The Three Worlds of Gulliver" was composer Bernard Herrmann's own favourite among the scores he wrote for Harryhausen and Schneer. Schneer considered "The 7th Voyage of Sinbad" Herrmann's best work for one of his productions.