Victimization and family rejection of sexual orientation are two salient stressors facing gay, lesbian, and bisexual (GLB) young people. While initial research has established a link between these sexuality-related stressors and GLB youths' mental health outcomes, the factors that underlie this relationship remain unclear. The current study examines the role of negative GLB identity (i.e., negative feelings about one's own sexual orientation) in mediating the relationship between sexuality-related stress (i.e., victimization, family rejection) and youth outcomes (i.e., internalizing problems, substance use, and cigarette smoking). Participants included 81 GLB young people (ages 14 to 25 years) recruited through college groups, youth organizations, study advertisements, and friend referrals. Path analyses revealed that victimization and family rejection experiences were related to youths internalizing problems via negative GLB identity. However, stressors and health risk behaviors were not related through negative GLB identity, although some direct relationships between stressors, substance use, and smoking emerged. Limitations and implications of the present study are discussed.