Research has documented significant relationships between posttraumatic stress disorder (PTSD), aggression, and intimate partner violence (IPV). Most of these studies have focused on men and measured violence by self-report. This study examined (a) the association between PTSD and general aggression among women, (b) the association between IPV and PTSD among married and/or cohabitating couples, and (c) the concordance between self and collateral reports of IPV. One hundred twenty participants provided information about PTSD symptoms and general aggression toward others, and 43 married and/or cohabitating couples provided information about PTSD and IPV. Women with PTSD reported more general aggression, IPV perpetration, and IPV victimization. Collateral informants of those with and without PTSD did not differ significantly in their report of IPV. Concordance between participants and spouses or partners was low to moderate. These results are discussed within the context of extant IPV literature.