BACKGROUND: Internalized homophobia (IH) is the internalization of homophobic attitudes by sexual minorities due to social bias. IH has been inconsistently related to substance use and condomless sex for young men who have sex with men (YMSM). PURPOSE: We examined negative urgency (the tendency to act impulsively in response to negative emotional experiences), positive urgency (the tendency to act impulsively in response to positive emotional experiences), and sensation seeking as independent moderators of the association of IH with binge drinking, drug use, and condomless anal sex. METHODS: Data were collected from 450 YMSM (mean age = 18.9) over the course of 18 months (baseline, 6-, 12-, and 18-month follow-up). RESULTS: Hierarchical generalized linear modeling revealed that there was a significant moderation for binge drinking and receptive condomless anal sex, with the association between IH and these risk behaviors increased for those with higher levels of negative urgency and positive urgency. CONCLUSIONS: IH is important to the negative health outcomes of binge drinking and condomless anal sex for individuals high in negative and/or positive urgency, who may act impulsively to avoid subjective negative experiences or in the face of positive emotional experiences. Future research is needed to further establish additional conditions under which IH may be important to understanding risk behaviors in YMSM, which is essential to developing targeted prevention and intervention efforts.