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 Dirty Harry (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".
Clint Eastwood was originally going to direct this movie. After taking over as director of The Outlaw Josey Wales (1976), though, he found himself having to supervise the editing of that movie and lacked time to fully prepare himself to both act and direct in another movie so soon. He promoted James Fargo, who would have been this movie's assistant director, to full director. Eastwood directed the next Dirty Harry movie, Sudden Impact (1983).
According to director James Fargo, the armed robber inside the liquor store improvised when he booted Harry in the ass.
Fritz Manes: Clint Eastwood's regular producing partner as a detective. The appearance was one of seven that Manes made in Eastwood's movies.