This film is a re-edited version of the pilot episode for El agente secreto de C.I.P.O.L. (1964), plus footage from at least one other episode, with a number of changes. The famous character of Mr. Waverly is not in this film, for example.
At the time this episode was made, there was a question as to what the name of the enemy spy agency would be. For this film version, Robert Vaughn dubbed the word 'WASP' for all characters, but later, it was discovered that that was the name of the hero agency in the other TV series Stingray (1964), so the name THRUSH was used in the TV pilot.
The somewhat tenuous connection between U.N.C.L.E. and 007 sort-of begins here, with both Luciana Paluzzi (later of Thunderball the following year) and Richard Kiel (of several later Bond movies as Jaws) both appear in this redressed version of the UNCLE pilot.
Released in the U.K. in 1965 as the second feature with Nunca comprarás mi amor (1964). This cinema release occurred just a few weeks before "The Man From UNCLE" began its very popular run on British television in the summer of 1965.