||Sexual minority (i.e., lesbian, gay, bisexual, and other nonheterosexual) men and women are at elevated risk for a number of mental and physical health concerns, including depression, alcohol and substance abuse, and physical health complaints. Minority stress theory has emerged as the most well-studied and compelling theory for the existence of these health disparities. However, studies of minority stress and health have generally not considered the specific context of romantic relationships. This is despite a large body of literature among heterosexual couples linking relationship quality with health. These converging lines of research suggest that the romantic relationships of sexual minority men and women are likely a critical, but understudied, context to consider when investigating the effects of minority stress on well-being. The current study tested a model where minority stress negatively impacts mental health, relationship satisfaction, and health behaviors among same-sex couples, with couples' interactions during conflict as a mechanism for effects on relationship satisfaction. Using an observational design conducted over the Internet, a sample of 60 (50% male, 50% female) same-sex couples was recruited across the U.S. By design, 40% of couples screened positive for significant relationship distress. Results demonstrated that minority stress was associated with relationship satisfaction and couples' observed interactions, although interaction behavior did not mediate effects of minority stress on relationship quality. Dyadic effects of minority stress on depression and substance use were also observed. Findings suggest that future studies of minority stress should take into account the social environment the surrounds the individual who experiences such stress. In addition, the effects of minority stress on relationship satisfaction indicate the need for culturally sensitive conceptualizations of same-sex couples' functioning, both clinically and in romantic relationship research.