The Revised Conflict Tactics Scales (CTS2) is frequently used to assess intimate partner violence (IPV), but consistently yields low to moderate interpartner concordance of reports. Interpartner concordance on an alternative measure, the Event History Calendar Interview (EHCI), is largely unknown. We observed limited interpartner concordance of IPV reports on the CTS2 and EHCI, with wives generally reporting more IPV than husbands. Compared with the CTS2, the EHCI detected more cases of IPV, but not differential behavior counts. Partners' posttraumatic stress disorder severity, a common respondent characteristic and focus of IPV research, was associated with low interpartner concordance of reports on the CTS2, but not the EHCI. Additionally, husbands' posttraumatic stress disorder severity was associated with wives reporting more husband-perpetrated IPV on the CTS2 than the EHCI. Overall, the EHCI appears to mitigate some of the problems associated with the CTS2 as a measure of IPV, particularly among more highly traumatized samples.