Because ethnicity is a basis for defining peer crowds in ethnically diverse American high schools, some may question whether crowds foster discrimination and stereotyping or affirm minority youths' positive ties to their ethnic background. Through examination of both self- and peer ratings of crowd affiliation among 2,465 high school youth aged 14-19 years, this study assesses the likelihood that African American, Asian American, Latino, and multiethnic adolescents are associated with ethnically defined crowds. Crowd affiliations are related to friendship patterns among all groups, positive features of ethnic orientation for Asian and Latino youth, but also some aspects of stereotyping and discrimination for Latinos. Results emphasize ethnic diversity in the role that peer crowds play in minority adolescents' social experiences.