Trevor Howard once said of this movie: "The best thing about 'Cockleshell Heroes' was filming in Portugal. Beautiful country. While I was there, I ended up doing the commentary for a documentary about the country which won more awards than the film ever did. I went all over the world promoting the documentary. As for the film, well."
José Ferrer was generally felt to be miscast as a British officer, as well as too old for his character.
Operation Frankton was far less successful than the film makes out. It was also a monumental failure of planning and communication that led to the loss of eight British soldiers' lives.
David Lodge often referred to this movie as a running joke in Spike Milligan's "Q" series.