After early roles in Howard Hawks's El Dorado (1966), Robert Altman's Countdown (1967) and Francis Ford Coppola's The Rain People (1969), he came to prominence for playing his signature role of Sonny Corleone in The Godfather (1972), for which he was nominated for the Academy Award for Best Supporting Actor and the Golden Globe for Best Supporting Actor. He reprised the role of Sonny Corleone in The Godfather Part II (1974) with a cameo appearance at the end.
Caan had significant roles in films such as Brian's Song (1971), Cinderella Liberty (1973), The Gambler (1974), Rollerball (1975), A Bridge Too Far (1977), and Alan J. Pakula's Comes a Horseman (1978). He had sporadically worked in film since the 1980s, with his notable performances including roles in Thief (1981), Gardens of Stone (1987), Misery (1990), Dick Tracy (1990), Bottle Rocket (1996), The Yards (2000), Dogville (2003), and Elf (2003).