Dialectical behavior therapy for posttraumatic stress disorder (DBT‐PTSD) is tailored for adults with PTSD from childhood sexual abuse (CSA). It uses principles from DBT and trauma‐focused cognitive–behavioral approaches. To evaluate acceptance and safety, the authors treated 29 women with chronic CSA‐related PTSD plus at least one other comorbid diagnosis. The Posttraumatic Diagnostic Scale (PDS), Symptom Checklist 90‐Revised, Beck Depression Inventory, and State Trait Anxiety Inventory were administered prior to, at the end of, and 6 weeks after 3 months of intensive residential treatment. An effect size of 1.22 on the PDS was found between baseline and follow‐up. Effect sizes for secondary outcomes ranged from medium to large. The results suggest that DBT‐PTSD has promise for reducing severe and chronic PTSD after CSA. Traditional and Simplified Chinese s by AsianSTSS