The authors report on changes in cognitions related to posttraumatic stress disorder (PTSD) among 54 female survivors of sexual and nonsexual assault with chronic PTSD who completed either prolonged exposure alone or in combination with cognitive restructuring. Treatment included 9-12 weekly sessions, and assessment was conducted at pretreatment, posttreatment, and a modal 12-month follow-up. As hypothesized, treatment that included prolonged exposure resulted in clinically significant, reliable, and lasting reductions in negative cognitions about self, world, and self-blame as measured by the Posttraumatic Cognitions Inventory. The hypothesis that the addition of cognitive restructuring would augment cognitive changes was not supported. Reductions in these negative cognitions were significantly related to reductions in PTSD symptoms. The addition of cognitive restructuring did not significantly augment the cognitive changes. Theoretical implications of the results are discussed.