Henry Hathaway was not too happy with this film, which he originally conceived as being far more light-hearted. He wanted William Powell and Dean Martin to play the leads. He was happy enough to have Edward G. Robinson as a replacement for Powell (who had retired), but was very dissatisfied with Steiger, who often refused to take direction and was reprimanded by the studio front office. "Christ, it was supposed to be a fun film - and Steiger is far, far from having a sense of humor", he was quoted as saying, in a 1974 interview.
A fifteen ton actual safe was used for the heist sequence. Rod Steiger and Michael Dante actually cracked the safe for the shooting, advised by technicians from the vault's manufacturer.
This was released less than six months before the strikingly similar heist film L'inconnu de Las Vegas (1960) (the original version starring Frank Sinatra and various members of his so-called "Rat Pack"). While "Oceans" was successful enough to merit a big budget remake and, in some circles, is considered a minor classic, "Thieves" came and went almost without notice and is mostly forgotten today.
Promotional materials for this film (as well as the opening credits) leaned rather heavily on Joan Collins' "exotic dance" routines. Fairly tame by today's standards, they were considered racy and blatantly erotic in 1960.