Joseph Losey and Harold Pinter were keen to make a film out of Nicholas Mosley's novel, but knew it would have to be a low-budget, intimate drama and that it would be difficult to find funding for it. Losey was certain that his friend and frequent collaborator Sir Dirk Bogarde would be the best casting for the role of "Stephen." When the famous producer Sam Spiegel expressed an interest in making the film, Losey and Pinter were tempted, because they knew he could find the money for it; but Losey was also cautious, having known and worked with Spiegel before, and also knowing that he liked to dominate his directors and impose himself on them. He was also sure that Spiegel was now only interested in lavish prestige productions. Sure enough, Spiegel insisted on hiring Richard Burton, then the highest-paid and most famous male film star in the world, to play "Stephen," hinting that, with Burton involved, an all-star cast could be obtained, and also making disturbing noises about the film becoming "more commercial". He invited Losey aboard his famous 378-foot yacht to discuss the film, and it was aboard this yacht, in the middle of the Mediterranean, that Spiegel offered Losey one of his special eight-inch cigars, which were prepared exclusively for him and which cost (in 1966) about £12 each (around £175-£200 in 2021 money). Losey, a non-smoker, accepted the cigar, made an elaborate show of piercing and lighting it, took two puffs and then threw it overboard, claiming it was "too dry." Furious, Spiegel immediately withdrew from the project and Losey was left free to make the small-scale film he wanted to make.
Delphine Seyrig (Francesca) shot her scenes in a day and a half. Her cameo appearance can be seen as something of an homage to one of Losey's favorite directors, Alain Resnais, in two of whose famous films, Last Year at Marienbad (1961) and Muriel (1963), Seyrig had starred.
Accident (1967) is the last of six films that Sir Dirk Bogarde and Joseph Losey made together. In chronological order, their collaborations were: The Sleeping Tiger (1954), Time Without Pity (1957), The Servant (1963), King & Country (1964), Modesty Blaise (1966) and Accident (1967).
The gondola-like boats are called punts and the activity shown in the film is called punting, which is still something one can do at Cambridge in 2023.