This cross-sectional study utilized data gathered from 350 lesbian, gay, and bisexual (LGB) youth, and examined the relationship between significant life experiences and posttraumatic stress symptoms (PSS), with an ultimate goal of analyzing contribution of sexual orientation victimization (SOV) to PSS among LGB youth. Results of bivariate analyses indicate that verbal and physical sexual orientation victimization, childhood gender atypicality, internalized homophobia, and stressful life events unrelated to sexual orientation were all individually related to PSS. Multivariate analysis showed that verbal and physical sexual orientation victimization explained a significant portion of variance, over and above the study's other variables. Internalized homophobia, stressful life events, and verbal sexual orientation victimization were found to be the most significant predictors of PSS among LGB youth.