Objectives. We examined perpetration of bullying among youths in vulnerable groups relative to youths in peer groups not categorized as vulnerable. Methods. Data were collected in 2013 from a large school-based survey of adolescents conducted in Minnesota (n = 122 180). We used the v2 test and logistic regression to compare measures of perpetration of physical and relational bullying, as well as experiences of victimization and perpetration (or both), across categories of sexual orientation, weight status, and disability status. Results. Rates of physical and relational bullying perpetration were significantly higher among youths in vulnerable groups than among those not in vulnerable groups. With respect to context of victimization experiences, young men and women from vulnerable groups were overrepresented in the group comprising both perpetrators and victims. For example, odds of being both a perpetrator and a victim were 1.41 to 3.22 times higher among gay, lesbian, and bisexual youths than among heterosexual youths. Conclusions. Vulnerable youths, who are prone to peer harassment, may also act as perpetrators of bullying. Prevention strategies should address the particular needs of these populations; targeted programming may be appropriate.