Powerful stereotypes exist about how female rape victims should act. For example, victims are expected to physically resist their attacker and immediately report their assault. In reality, some victims are too shocked to physically resist or too traumatized to immediately go to police. Nevertheless, counterstereotypic-victim behavior can undermine fair prosecution outcomes, especially for acquaintance-rape victims. In the current research, we examined the influence of perceivers’ cultural similarity to the perpetrator, and the stereotypicality of rape-victim behaviour, on victim and perpetrator blame, punishment severity, and guilt likelihood. We varied an acquaintance-rape scenario, to present stereotypical/counterstereotypical rape-victim behaviour, and the cultural similarity/dissimilarity of perpetrators to participants, who were White-Australian women and men, aged between 18 and 74 (N = 237). In the victim-stereotypic condition, reactions did not vary as a function of perpetrator-cultural similarity. However, in the counterstereotypic-victim condition, culturally similar (compared to culturally dissimilar) perpetrators were considered less guilty and less deserving of punishment. Moderated mediation indicated that the greater leniency shown towards culturally similar perpetrators was explained by increases in victim blame and decreases in perpetrator blame. To decrease bias when prosecuting rape perpetrators, we recommend challenging the selective use of counterstereotypic-victim behaviour to defend culturally similar perpetrators.