Although one of the greatest female dancers in the history of the movie musical, Cyd Charisse singing in films was almost always dubbed. A young Vikki Carr performed her singing in The Silencers.

In the scene where Matt Helm (Dean Martin) is checking into the Phoenix Hotel and Andreyev (Roger C. Carmel) is lurking in the foreground, the hotel newsstand is immediately behind him. The newsstand shelf is lined with books from Donald Hamilton's Matt Helm series, on which the movie is based.

The letters in the name of the BIG O criminal organization is an acronym. The organization's full name is the Brotherhood of International Government and Order.

The name "Tung-Tze" means "to rule" in Chinese.