As evidence builds for straight allies' contributions to battling sexual prejudice, barriers to assuming this role must be identified and dismantled. This study investigated stigma and stigma by association in perceptions of straight allies in a college population. Adjective rating items were completed by 505 participants who identified as heterosexual and not as lesbian, gay, bisexual, transgender, or queer/questioning. Results indicated stigma by association for the male heterosexual target, who was rated as more feminine in the ally than non-ally condition. Implications for research and ally training are discussed.