Updated: October 10, 2025

Filmed in color from late November to early December 1963, with locations at a Lever Brothers soap factory in California, the television pilot made as a 70 minute film was originally titled Ian Fleming's Solo and later shortened to Solo. However, in February 1964 a law firm representing James Bond producers Harry Saltzman and Albert R. Broccoli demanded an end to the use of Fleming's name in connection with the series and an end to the use of the name and character "Solo", "Napoleon Solo" and "Mr. Solo". At that time filming was underway for the Bond film Goldfinger, in which Martin Benson was playing a supporting character named "Mr. Solo", being an American Mafia boss murdered by Auric Goldfinger. The claim was the name "Solo" had been sold to them by Fleming, and Fleming could not use it again. Within five days Fleming had signed an affidavit that nothing in the Solo pilot infringed any of his Bond characters, but the threat of legal action resulted in a settlement in which the name Napoleon Solo could be kept but the title of the show had to change. Coincidentally, the TV series debuted only a few days after the Sept. 17, 1964 U.K. release of the Goldfinger movie with its "Mr. Solo" character, though U.S. release would not occur until 1965.

The role of the head of U.N.C.L.E. in the pilot was Mr. Allison, played by Will Kuluva, rather than Mr. Waverly, played by Leo G. Carroll, and David McCallum's Illya Kuryakin only had a brief role. Revisions to some scenes were shot for television, including those needed to feature Leo G. Carroll. The pilot episode was reedited to 50 minutes to fit a one-hour time slot, converted to black-and-white, and shown on television as "The Vulcan Affair".

Additional color sequences with Luciana Paluzzi were shot in April 1964, and then added to the pilot for MGM to release it outside the United States as a B movie titled To Trap a Spy. This premiered in Hong Kong in November 1964. The extra scenes were reedited to tone down their sexuality, and then used in the regular series in the episode "The Four-Steps Affair".

Beyond extra scenes for the feature film, and revised scene shots and edits made for the television episode, there are other differences among the three versions of the story. Before the show went into full production there was concern from Metro-Goldwyn-Mayer that the name of Thrush for the pilot's international criminal organization sounded too much like SMERSH, the international spy-killing organization in Fleming's Bond series. The studio suggested Raven, Shark, Squid, Vulture, Tarantula, Snipe, Sphinx, Doom sic, and Maggot ( The last used in early scripts ). Although no legal action took place, the name "WASP" was used in the feature version To Trap a Spy. The original pilot kept "Thrush" ( Presumably since it was not intended to be released to the public in that version ). Felton and Rolfe pushed for the reinstatement of "Thrush". It turned out that WASP could not be used, since Gerry Anderson's British television series Stingray was based on an organization called W.A.S.P. ( World Aquanaut Security Patrol ). By May 1964, Thrush was retained for the television episode edit of the pilot. Despite this, WASP was used by the feature film in Japan in late 1964, and it was left in the American release in 1966.

Another change among the three versions of the pilot story was the cover name for the character of Elaine May Donaldson. In the original pilot it was Elaine Van Nessen; in the television version and the feature version it was Elaine Van Every. Illya Kuryakin's badge number is 17 in the pilot, rather than 2 during the series, and Solo's hair, after new footage was added, changed back and forth from a slicked back style to the less severe style he wore throughout the series.

With the popularity of the show and the spy craze, To Trap a Spy and the second U.N.C.L.E. feature The Spy with My Face were released in the United States as an MGM double feature in early 1966.