Le plus escroc des deux

The teaser trailer features a sequence which does not appear in the final movie. Freddy Benson and Lawrence Jamieson walk along a boardwalk, politely moving out of the way of other people, etc. with a voiceover saying "There are numerous distinguished gentlemen in the world; refined, cultured gentlemen; nice men; but nice men finish last." As the last few lines are spoken, Freddy pushes an old lady into the water, and Lawrence shoves a child's face into his cotton candy. Director Frank Oz has said that audiences were very surprised to learn that the scene was not part of the finished movie

When Lawrence Jamison goes to Switzerland, the sign in the train station reads "ZURICH". It should read "ZÜRICH" with an umlaut.

While the names of Stanley Shapiro and Paul Henning appear in the credits as two of this film's three writers, they are actually there just to credit their script for Les séducteurs (1964), of which this is a remake.

Edited into Alias: The Enemy Walks In (2002)