The film's backers insisted that a name actor be cast in the lead, over the unknown Kenneth Haigh who had been so successful in the stage version. Richard Burton agreed to take on the part at a much lower fee than his usual Hollywood salary.
According to Burton biographer Paul Ferris, Salzman screened the film as a courtesy to Jack Warner, who put up the money for the picture. After a few minutes, Warner asked sarcastically what language they were speaking. When Salzman told him it was English, the studio chief replied, "This is America!" and walked out.
Initially Harry Saltzman was opposed to the idea of Tony Richardson directing the film version as he had never directed a film before. John Osborne insisted on Richardson as he had been responsible for the theatrical version but Saltzman's opposition led to the film's original backers, J. Arthur Rank, pulling out of the deal. Osborne of course ultimately got his way.
Theater critic Kenneth Tynan persuaded Nigel Kneale to extend the play into a screenplay. John Osborne was so delighted that he didn't have to perform the task that he happily signed over the story rights for a mere £2,000.
Tony Richardson originally intended to cast John Fraser as Jimmy Porter, and Fraser was even sent to the Cannes Film Festival, where his casting was announced to the press. However, when Richardson's producing partner John Osborne happened to meet Richard Burton in New York, Burton told Osborne he would kill to play the role, and Burton was subsequently cast instead.