Pola Negri had been retired for about twenty years when Walt Disney himself convinced her to come out of retirement to make this film. Studio executive and the film's co-producer, Bill Anderson, telephoned Negri at home in Texas, and convinced the veteran actress to read the screenplay, after going to Hollywood to negotiate the project.
Despite good reviews, and Hayley Mills' popularity with young audiences at the time, the film failed at the box office. Rather than being re-issued in theaters, it was initially shown two years later, in three parts, on the Disney Sunday night TV show.
There are significant differences between the movie and the novel: in the book, Nikki Ferris arrives in Agios Georgios a day ahead of her aunt and finds Mark wounded in a hut on her way to the village. Mark has been shot by Sophia's husband, a collaborator with Stratos, who has stolen the Camford jewels in London from Mark, who was the courier. Another collaborator is the British gay man who is the hotel clerk - there is no British diplomat in the original story. Mark and his friend Lambis are trying to find Mark's teen-aged brother Colin. Nikki is OLDER in the book than in the film and a minor secretary for the British Embassy (an earlier trivia statement is incorrect here), Mark's last name is actually Langley, and Colin was actually the captive in the windmill. Beyond the title of the movie, there are few similarities between it and the book.
The meaning and relevance of the film's "The Moon-Spinners" title is that it refers to a Cretan inn hotel owned by Sophia (Irene Papas) where Nikky (Hayley Mills) and Aunt Frances Ferris (Joan Greenwood) stay. In the movie, it is also referred by a character as being a Greek restaurant in Soho.
One of the most notable Hitchcockian style thriller scenes in the picture was the windmill suspense sequence. Alfred Hitchcock had previously directed one in 1940's Foreign Correspondent (1940) around a quarter of a century earlier.
This feature film was distributed in the USA with the forty minute Disney support short Yellowstone Cubs (1963) which had previously been released as part of a double-feature bill with Disney's Savage Sam (1963).
In the film's source novel of the same name by Mary Stewart the lead character of Nikky Ferris (Hayley Mills) travels alone but in this movie adaptation she is accompanied by her Aunt Frances Ferris (Joan Greenwood).
Playing Madame Habib in this cinema movie, this was the first theatrical feature film of actress Pola Negri since she had portrayed Genya Smetana in Hi Diddle Diddle (1943), an interval of around twenty one years.