Dating in adolescence plays an integral part in the development of sexual and social identities. This process is particularly salient for sexual minority youth who face additional obstacles to their identity formation due to their marginalized status. We investigated the influence of participating in a same-sex relationship (SSR) or an opposite-sex relationship (OSR) on sexual minority youths' psychological well-being (i.e., symptoms of depression, anxiety and internalized homophobia, and self-esteem) in an ethnically-diverse sample of 350 youth (55% male) between the ages of 15-19 years, recruited from three GLBT drop-in centers in the New York City area. Using longitudinal data, we examined youths' SSR and OSR over time. Multivariate regression analyses suggest that involvement in a SSR was positively associated with changes in self-esteem in males, and negatively correlated with changes in internalized homophobia in females. We discuss the implications for positive development in sexual minority adolescent populations.