Ethnic/racial context in peer groups is poorly understood. Using daily data from 178 ethnically/racially diverse adolescents (M age = 14.53) over 2 weeks, this study investigated peer processes related to ethnicity/ race (peer ethnic/racial processes) in everyday life. On average, peer ethnic/racial processes occurred about 1 to 4 days over the 2 weeks. On days when adolescents reported more negative peer ethnic/racial processes (indicated by ethnic/racial teasing, discrimination, victimization, and partially by preparation for bias), they also reported lower school engagement. On days when adolescents reported more positive peer ethnic/racial processes (indicated by cultural socialization, support against discrimination, and partially by preparation for bias), they exhibited more prosocial behaviors and greater ethnic/racial identity private regard. Similar associations emerged at the between-person level. This research is supported by the William T. Grant Foundation. The content is solely the responsibility of the author and does not necessarily represent the official views of William T. Grant Foundation. The author also thanks Drs. Tiffany Yip and Aprile D. Benner for their helpful feedback on this project.