Fourteen heterosexual rapists and 14 men who were not sex offenders participated in the study. Twelve subjects had been charged with rape, attempted rape, gross indecency, or indecent assault involving a female victim 16 years of age or older, and two subjects had been charged with homicide that occurred as part of a sexual assault. All rapists had been admitted to a maximum security psychiatric institution for assessment. The 14 comparison subjects included three nonsex offender patients from the same institution and 11 men recruited from the local community. All subjects were presented with audiotaped narrations while their penile tumescence was measured. Stories described a male-female interaction; response categories included rape with victim enjoyment, rape with victim suffering, nonsexual assault by the man, and consenting sexual and nonsexual heterosocial interaction. In each category, stories were told from either the woman's or the man's point of view. Overall, subjects showed higher arousal to stories described from a female perspective. Consistent with the lack of empathy account of rape, rapists were less empathic than nonrapists and deviant arousal was inversely related to self-reported empathy. The best discrimination between groups was obtained for rape stories told from the point of view of a suffering victim. The finding that all rapists but no nonrapists preferred rape stories over consenting sex stories, however, suggested that the lack of empathy account of rape was incomplete. Data indicated that cues of violence and victim distress contributed to sexual arousal among rapists. 32 references and 2 figures