When Harry meets Uhuru leader, Mustapha (Albert Popwell), he asks "Where do I know you from?" Popwell played a bank robber in Dirty Harry (1971), a pimp in Magnum Force (1973), and Horace in Sudden Impact (1983). He didn't appear in The Dead Pool (1988).
According to Clint Eastwood biographer Marc Eliot, screenwriter Stirling Silliphant suggested Tyne Daly for her role, but she turned down the script three times before finally deciding on doing it. Daly also suggested that the romantic attachment between her character and Callahan be omitted. Eastwood agreed.
When Harry, (Clint Eastwood) is about to intervene in the convenience store siege, his partner Inspector Frank DiGeorgio (John Mitchum) asks if he needs help, but Harry responds that he "may need to move fast and doesn't need too much linguini slowing him down". This is a reference to Ispettore Callaghan: il caso 'Scorpio' è tuo!! (1971) when DiGeorgio could not climb over the fence with Harry to get into the football stadium, due to his weight, with the excuse "Too much linguini".
This was intended to be the final movie in the Dirty Harry film franchise, but, after a string of box-office failures, Clint Eastwood was persuaded to resurrect the character for "Sudden Impact" in 1983.
Tyne Daly says that the only time she ever saw Clint Eastwood get angry was when they were filming the climactic scene between her character and his and a production manager was hurrying the crew to wrap it up. Eastwood snapped that they had made it this far and that there was no need to get cheap now. His wishes were followed and they kept shooting until Eastwood was happy with the shot.
Fritz Manes: Clint Eastwood's regular producing partner as a detective. The appearance was one of seven that Manes made in Eastwood's movies.