21 Grams is a 2003 American drama film directed by Mexican director Alejandro González Iñárritu from a screenplay written by Guillermo Arriaga. It stars Sean Penn, Naomi Watts, Charlotte Gainsbourg, Danny Huston and Benicio Del Toro.Like Arriaga's and González Iñárritu's previous film, Amores perros (2000), 21 Grams interweaves several plot lines, around the consequences of a tragic automobile accident.