Private Henry Hook was required to be in the field hospital, which consisted mostly of interior shots. Therefore, James Booth did not travel with the cast and crew to South Africa for filming.
Michael Caine only earned £4,000 for his role. Stanley Baker and Jack Hawkins were the highest paid actors, with £30,000 each.
One of this movie's technical advisors was a Zulu Princess, and the tribe's historian. She knew the battle strategy perfectly, and drew it on the sand. Director Cy Endfield shot it exactly as she drew it.
Chief Mangosuthu Buthelezi, who comes from a long line of Zulu warriors and royalty, played his great-grandfather, King Cetewayo. In an interview, he said the director had identified a radio announcer to play the part, "but when he saw me he said that he saw a family resemblance and persuaded me to take part as an extra."
The historical Colour Sergeant Bourne was 24 during the defence of Rorke's Drift (Nigel Green, who played him, was 40). He was the last defender of the post to die as an honorary Lieutenant Colonel, on V.E. Day, May 8, 1945, age 91.