OBJECTIVE: Trauma-exposed individuals with post-traumatic stress disorder (PTSD) display reduced amygdala and hippocampal size and impaired cognition. However, studies on trauma-exposed individuals with dissociative amnesia (DA) or dissociative identity disorder (DID) are lacking. METHOD: Twenty-three young women who had experienced severe childhood sexual/physical abuse, diagnosed with DA/DID or PTSD, and 25 healthy control subjects were subjected to 3D structural magnetic resonance imaging of amygdala and hippocampus and a clinical and neuropsychological investigation. RESULTS: Compared with controls, trauma-exposed subjects with PTSD (n = 10) displayed significantly reduced amygdala and hippocampal size and significantly impaired cognition. By contrast, trauma-exposed subjects with DA or DID (n = 13) displayed normal amygdala and hippocampal size and normal cognition. CONCLUSION: We report for the first time volumetric results in subjects with DA/DID without PTSD as comorbid diagnosis. Our results indicate preserved amygdala and hippocampal size and preserved cognition in subjects with these disorders.