- California Doubling: The picture was filmed in Yugoslavia, as a stand-in for the Mauritanian coast and Gibraltar. Sidney Poitier called Belgrade the worst location in which he had ever filmed.
- Creator Backlash: Richard Widmark refused the role of Rolfe several times, and confessed that he felt he was too old for the role after filming wrapped up.
- Follow the Leader: The film was made to cash in on the popularity of 1958's The Vikings, even having the latter's cinematographer, Jack Cardiff, as director, as well as some props from it according to rumors. Ernest Borgnine was even the producers' favorite choice to play Al Mansuh.
- What Could Have Been:
- As mentioned above, Ernest Borgnine was the producers' first choice to play Al Mansuh. Richard Widmark turned down the role of Rolfe four times before finally agreeing to do it on the condition that his good friend Sidney Poitier do the part of Al Mansuh. Producers initially objected before accepting. They also dodged a blackface bullet this way.
- Director Jack Cardiff initially wanted Ursula Andress for the part of Gerda.
- Robert Taylor was originally in the running for the part of Rolfe.
Trivia / The Long Ships