Robert Shaw desperately wanted the role of Sinbad but was placated by being cast uncredited as the Oracle. His face was heavily swathed in make-up and his voice electronically altered by a sound engineer.
The closed-captioner for this movie decided to have some fun with Prince Koura's lines. When Koura says his unintelligible magic spells to summon the dark spirits against Sinbad and his crew, the captions for the first time he does that read, "SSFUP AOCOC ROF OOKCUC MI" (which is IM CUCKOO FOR COCOA PUFFS spelled backwards); and subsequently, "TTIBBAR YLLIS. YLNO SDIK ROFERA XIRT" (that reverses to TRIX ARE FOR KIDS ONLY. SILLY RABBIT).
When Sinbad and the others land on Lemuria there is a cliff along the left side of the beach with carvings on it. According to an interview given by Ray Harryhausen this cliff doesn't actually exist. The scene was shot on a popular beach in Spain and the cliff is a matte painting that was put in to hide all the spectators.
Harryhausen paid tribute to one of his inspirations, The Thief of Bagdad (1940), with this film. Both had the same composer, and Kali's dance copies many moves of the six-armed robot in the 1940 film. The Hindu-style temple in the 1940 film is echoed in the Hindu-style carvings of Lemuria, and the look of the Lemurians is based on the 1940 film as well; there are other echoes and influences to be seen by those familiar with both films.