Abstract: Objective: This randomized trial tested the effectiveness of Skills Training in Affective and Interpersonal Regulation (STAIR) compared to present-centered therapy (PCT) delivered virtually to women veterans who had experienced military sexual trauma (MST) and screened positive for posttraumatic stress disorder (PTSD). Method: One hundred sixty-one eligible women veterans were randomized into the study. The primary outcome was clinician-assessed PTSD severity (Clinician-Administered PTSD Scale-5), while secondary outcomes included social support and several other symptom measures at posttreatment through 2- and 4-month follow-up. Results: PTSD severity decreased in both conditions by posttreatment but significantly more (p = .028, d = 0.39) in STAIR (d = 1.12 [0.87, 1.37]) than PCT (d = .78 [0.54, 1.02]). STAIR was also superior in improving social support and emotion regulation and reducing depression and negative cognitions. Improvement in psychosocial functioning was moderate and did not differ between conditions. All changes were maintained through 2- and 4-month follow-ups. Dropout rates were low and did not differ (19.0% and 12.2%, respectively). Conclusion: STAIR provided superior outcomes compared to PCT regarding PTSD, social support, and multiple types of mental health problems among women veterans with MST. The application of STAIR to other populations with social support and related concerns warrants investigation. The substantial effect sizes for PTSD symptoms in both treatments suggest that they are practical alternatives for individuals who do not wish to participate in trauma-focused therapy and may increase engagement in mental health services.