'Francois Truffaut' claimed this movie was his favorite Hitchcock and the best representation of Alfred Hitchcock's work.
Orson Welles reportedly saw this film eleven times.
A musician is mysteriously strangled by disembodied hands after serenading Miss Froy under her hotel window. This is not one of the film's loose ends as previously reported. Froy uses a musical code and the singer can be assumed to be passing information to Froy. Note that Froy is carefully listening to the notes, not just enjoying the serenade. The singer is an informant or another spy.
Although he uses the fictitious Bandrikan language when speaking to his staff, at the end of the phone conversation in which he conveys Iris's room service order for "champagne", Boris, the harassed hotel manager, exclaims, "Oy vey is mir", a Yiddish expression meaning "woe is me."
Charters and Caldicott (played by Basil Radford and Naunton Wayne) proved to be such popular characters that they were teamed up in other films. They reappeared in Night Train to Munich (also starring Margaret Lockwood) and Millions Like Us, two films also written by Sidney Gilliat and Frank Launder. They also starred in the BBC Radio serials "Crook's Tour" (which was also made into a film), and "Secret Mission 609." In 1985, they reappeared in the BBC Television mystery mini-series, Charters & Caldicott, played by Robin Bailey and Michael Aldridge.
Gilbert says he once drove "a miniature engine on the Dymchurch line". The Romney, Hythe and Dymchurch Railway is a real-life miniature (1/3 normal size) railway in southeast England, which in 2003 still uses steam locomotives and carries passengers over 13 miles of route.
In the original cut, as seen in the 25th Anniversary national re-release of 1963, Charters and Caldicott have to share the same pair of pyjamas in the hotel after Charters has accidentally dropped his in the water jug. In later years and showings this innocent preamble has been snipped out and we cut straight to them in bed together. Though we can still see Charters' pyjamas hanging up to dry during the scene the explanation has disappeared.
The brief shot of a ferry bringing Iris and Gilbert back to England (presumably across the English Channel) also appears as an Irish Sea ferry in Will Hay's Oh, Mr. Porter!.
The cricket match that is being talked about in the movie by Charters (Basil Radford) is the description of the actual third Ashes test between England and Australia at Manchester in 1938. The result of the test match quite rightly was shown in the end through a newspaper headline - "Match abandoned due to rain".
The fictitious country where most of the story takes place is named in the movie: in her first scene, Miss Froy says, "Bandrika is one of Europe's few undiscovered corners." The first two stations in the movie are identified by briefly visible signs, and the third in dialog: they are Zolnay, Dravka, and Morsken.
The film debut of Catherine Lacey.
The set that the movie was shot on was only ninety feet long.
Alfred Hitchcock:
near the end of the movie at Victoria Station wearing a black coat and smoking a cigarette.