Men are more likely to be blamed more for intimate partner violence (IPV) than are women who commit the same offense. However, because men are typically stronger and perceived as more physically aggressive than women are, perpetrator sex is confounded with masculinity and the ability to arouse fear in the victim. This study disentangled the construct of gender in understanding bystanders’ attributions of blame in IPV. Participants (N = 639) read a scenario in which the perpetrator’s sex (male/female) and gender identity (masculine/feminine), and the victim’s sex (male/female) were manipulated and rated how much they blamed the perpetrator and the perpetrator’s ability to arouse fear of injury in the victim. Results showed that male perpetrators (regardless of gender identity) who assaulted a female victim were attributed the most blame and were perceived as having the greatest ability to arouse victim fear. In contrast, feminine female perpetrators were attributed the least blame and perceived as arousing the least victim fear regardless of the victim’s gender. Furthermore, controlling for the perpetrator’s ability to arouse fear in the victim resulted in the elimination of the interaction effects for blame. This finding suggests that perpetrators’ ability to arouse fear is an underlying factor in bystanders’ attributions of blame.