Do experiences with racial discrimination at school predict changes in African American adolescents' academic and psychological functioning? Does African American ethnic identity buffer these relations? This paper addresses these two questions using two waves of data from a longitudinal study of an economically diverse sample of African American adolescents living in and near a major East Coast metropolis. The data were collected at the beginning of the 7th grade and after the completion of the 8th grade. As expected, experiences of racial discrimination at school from one's teachers and peers predicts declines in grades, academic ability self-concepts, academic task values, mental health (increases in depression and anger, decreases in self-esteem and psychological resiliency), and increases in the proportion of one's friends who are not interested in school and who have problem behaviors. A strong, positive connection to one's ethnic group (our measure of ethnic identity) reduced the magnitude of the association of racial discrimination experiences with declines in academic self-concepts, school achievement, and perception of friends' positive characteristics, as well as the association of the racial discrimination experiences with increases in problem behaviors.