Numerous studies in the area of sexual assault have examined false or stereotypical beliefs about rape victims, in other words, rape myths, but virtually all of these studies have limited themselves to female victims and male perpetrators. The purpose of the present research is to examine myths about community dwelling adult male victims of sexual assault, a group that has been largely ignored by both the public and the scientific community. In Study 1, 303 undergraduates completed 80 items intended to measure belief in male rape myths, and a criterion measure consisting of 6 male rape vignettes. These measures were completed on two occasions separated by a 4-week interval. Using four separate criteria of item quality, 22 items were selected to create the Male Rape Myth Scale, a reliable and valid self-report instrument for measuring false or stereotypical beliefs about the sexual assault of adult men. In Study 2, 304 undergraduates completed the Male Rape Myth Scale and a number of other personality and attitudinal measures. Results of multiple regression analyses demonstrated that belief in male rape myths can be best predicted by negative attitudes toward homosexuality and the belief that men should not have or express certain feelings. The results of these studies confirm the widespread existence of false beliefs about male rape victims and suggest that these myths may originate in respondents' beliefs about male sexuality and masculinity.