This study examined whether a history of childhood sexual abuse (CSA) influenced treatment outcome among female veterans with an index trauma of military sexual trauma (MST) receiving residential treatment for posttraumatic stress disorder (PTSD). One hundred and ten female veterans, 61 with a history of CSA and 49 without, were compared on pre-treatment demographic and symptom measures, as well as treatment outcome, which were assessed with the Clinician-Administered PTSD Scale (CAPS), PTSD Checklist–Stressor Specific Version (PCL-S), and Depression Inventory–Second edition (BDI-II). Veterans received cognitive processing therapy (CPT) as the primary trauma-focused treatment. Study findings showed that these two groups did not significantly differ on pre-treatment variables or treatment outcome. Results suggest that CPT delivered in a residential treatment program was effective for female veterans with PTSD related to MST, with and without a history of CSA.