This research examines cross-ethnic friendships as a predictor of perceived discrimination and support for ethnic activism over time among African American, Latino American, and Asian American undergraduate participants from a multi-year, longitudinal study conducted in the United States. Our research builds on prior cross-sectional research by testing effects longitudinally and examining how relationships among these variables may differ across ethnic minority groups. Results indicate that, over time, greater friendships with Whites predict both lower perceptions of discrimination and less support for ethnic activism among African Americans and Latino Americans, but not among Asian Americans. Implications of these findings for future research on inter-group contact, minority–majority relations, and ethnic group differences in status are discussed.