George Lazenby's character "JB" was intended to be James Bond, and a nod to Ian Fleming, who helped in the creation of the original The Man from U.N.C.L.E. (1964). Legal concerns resulted in explicit references to Bond being dropped, though there was little doubt who the character was supposed to be. A female character, on seeing "JB," says "it's just like Her Majesty's Secret Service," a reference to the Bond film that starred George Lazenby.
When they were filming this reunion movie, both lead actors were asked how the success of the original show affected their careers. David McCallum said that he was often typecast and found it difficult to play other types of roles, Robert Vaughn said in his case the opposite was true, he played nothing but villains after the series ended.
Even though Leo G. Carroll, who played U.N.C.L.E. boss Alexander Waverly in the T.V. series, passed away in 1972 he still makes an appearance in this movie. His photograph can be clearly seen sitting on a table behind behind the desk of U.N.C.L.E. receptionist Ms. Friday.
During the car chase, Markovitch remarked that the chase reminds her of the film Bullitt (1968) to which Napoleon Solo replies that he remembered the said film. Robert Vaughn, who played Napoleon Solo also appeared on Bullitt.
As well as featuring past Bond actor George Lazenby, the film also features two actors who would later appear in Bond films: Patrick MacNee (Tibbet in A View to a Kill (1985)) and Anthony Zerbe (Milton Krest in Licence to Kill (1989)).