This study assessed college women's reactions to participating in sexual assault research. Women with sexual victimization histories reported more negative emotional reactions than nonvictimized women, but also greater benefits. Benefits to research participation outweighed costs for both women with and without sexual victimization histories. Women with and without sexual victimization histories evidenced significant improvements in several domains of mood over the course of the study, although victimized women improved less in several areas of mood. Participants' presurvey mood, assault severity, perpetrator aggression, self-blame, and perceived benefits to research participation all uniquely predicted participants' immediate negative emotional reactions to the research protocol. Descriptive analyses showed that only a small number of women reported negative emotional reactions to the research protocol.