The animation/graphics seen on the bridge station display monitors were projected from behind the bridge set walls by dozens of 16 mm projectors (one for each display screen), as computer technology was not advanced enough at the time to use real computer monitors on a practical basis. As a result, the clattering sound of the noisy projectors nearly drowned out the voices of the actors, and their dialogue had to be dubbed over later at considerable added time and expense.
Kirk and Khan never meet face to face during the movie. All of their interaction is through viewscreens or communicators. This was because Ricardo Montalban filmed his scenes separately from the main production in order to accommodate his schedule of filming Fantasy Island.
In the opening credits, there is an extra long pause between William Shatner and DeForest Kelley's names, where Leonard Nimoy's name would normally be.
While attempting to escape from the security agents aboard the USS Enterprise, Chekov tosses his phaser to one of the agents; although it is representative of twenty-third century technology, it is never retrieved.
This film marks the largest living thing Spock neck pinched: a horse.
According to Nicholas Meyer, Brock Peters found Admiral Cartwright's words during the briefing scene to be so offensive he needed several takes to get them all out. In a similar vein, Nichelle Nichols refused to speak the line 'Guess who's coming to dinner?' - an intentional reference to Guess Who's Coming to Dinner - which is heard prior to the Klingons' visit to the Enterprise. The line was instead given to Walter Koenig (Chekov).
The producers asked George Takei to come back and play Sulu one more time, and take the helm of the Enterprise-B. But Takei refused because if Sulu had taken the helm, it would have meant temporarily reducing Sulu's rank, so that he could serve under Captain Kirk again. He felt that Sulu had worked too hard to earn his command to allow even a temporary reduction.
In an early draft of the screenplay, the character Lt. Hawk (Neal McDonough) was gay, and therefore was to have been the first openly gay character in any Star Trek series or movie; however, any reference to his sexual orientation was excised from later drafts of the screenplay. Lt. Hawk was later confirmed as having been gay in the Star Trek tie-in novel Section 31: Rogue by Andy Mangels and Michael A. Martin.
So far, this is the only Star Trek movie in which absolutely no scenes take place on or near Earth.
Patrick Stewart was paid nearly as much for this movie as he made in the entire run of Star Trek: The Next Generation.
To perfect the Vulcan salute, Zachary Quinto had his fingers glued together by J.J. Abrams.
Screenwriters Roberto Orci and Alex Kurtzman explained that the dilemma for the sequel was whether to pit the crew against another villain, or to have an 'exploration sci-fi plot where the unknown and nature itself is somehow an adversary.'