This study examined evidence for a dissociative subtype of post-traumatic stress disorder (PTSD) among women seeking psychotherapy for childhood sexual abuse (CSA). One hundred and twenty-two women seeking treatment for CSA completed a battery of questionnaires assessing PTSD, dissociative symptoms, and child maltreatment. Using signal detection analysis, we identified high and low dissociation PTSD subgroups. A constellation of three PTSD symptoms-hypervigilance, sense of foreshortened future, and sleep difficulties-discriminated between these two subgroups (OR = 8.15). Further evidence was provided by the finding of a nonlinear relationship between severity of childhood maltreatment and dissociation in the women with PTSD. These results provide support for a dissociative subtype of PTSD that may stem from more severe childhood experiences of neglect and abuse.