Tony Curtis was very keen to make the film as he saw it as an opportunity to break out of the mindless, pretty boy roles he was usually assigned. Director Stanley Kramer initially had some misgivings but ultimately relented.
Robert Mitchum turned down the Tony Curtis' role. Mitchum, a real-life veteran of a Southern chain gang, said that he didn't believe the premise that a black and white man would be chained together, as such a thing would never happen in the very strictly segregated South. Over the years, this reason was corrupted to the point where many people now believe Mitchum turned down the role because he didn't want to be chained to a black man, an absolute falsehood. Curtis repeated the inaccurate story in his autobiography, but since has recanted after it was explained to him.
The film's co-writers, Nedrick Young and Harold Jacob Smith, were cast as the prison truck drivers, with the writing credits below their faces, because Young was blacklisted and writing under a pseudonym at the time and producer Stanley Kramer wanted to identify them truthfully.