i know what you did last summer is a 1997 american teen slasher movie. the movie is based on the novel of the same name by lois duncan. the movie was directed by jim gillespie. it stars jennifer love hewitt, freddie prinze, jr., sarah michelle gellar, matthew lillard, neve campbell and ryan phillippe. the writer is kevin williamson (the writer of "scream"). it was followed by two sequels: "i still know what you did last summer" and "i'll always know what you did last summer".