Evelyn Waugh disowned this movie of his famous novella and tried unsuccessfully to get his name taken off of the credits. Three days after the movie's London opening, he died unexpectedly at his house in Somerset. It is thought that he had not seen it.
American Robert Morse had such trouble keeping up his "British" accent that eventually all of his dialogue had to be recorded in a studio and dubbed over the movie.
Director of Photography Haskell Wexler was dissatisfied with some of the outdoor Whispering Glades scenes because they were being filmed at noon, and the trees were not casting significant shadows, which he felt was necessary to give the shot proper depth. To compensate, he had the crew paint tree "shadows" on the ground. This is plainly visible in some scenes, as the trees' "shadows" are entirely dissimilar from those of the actors standing next to them.
In the movie, Sir Francis Hinsley (John Gielgud) is hired to make an English gentleman of hick cowboy star Dusty Acres, played by Robert Easton, including teaching Acres to speak the King's English. In real-life, Easton was renowned as one of the movie industry's most respected elocution coaches.
Jamie Farr: Near the beginning, as the restaurant busboy who replaces the portrait of President Lyndon B. Johnson with a painting of Queen Elizabeth II.