In this randomized controlled clinical trial, the authors evaluated the effectiveness of cognitive processing therapy (CPT) in the treatment of self-reported and clinician-assessed posttraumatic stress disorder (PTSD) related to military sexual trauma (MST), along with depressive symptoms. Eighty-six veterans (73 female, 13 male) randomly assigned to receive 12 individual sessions of either CPT or present-centered therapy (PCT) were included in analyses. Blinded assessments occurred at baseline, posttreatment, and 2, 4, and 6 months posttreatment. Mixed-effects model analysis revealed a significant interaction between groups (p = .05, d = -0.85): At posttreatment, veterans who received CPT had a significantly greater reduction in self-reported, but not clinician-assessed, PTSD symptom severity compared to veterans who received PCT. All three primary outcome measures improved significantly, both clinically and statistically, across time in both treatment groups. Pre- and posttreatment effect sizes were mostly moderate to large (d = 0.30-1.02) and trended larger in the CPT group. Although the study was impacted by treatment fidelity issues, results provide preliminary evidence for the effectiveness of CPT in reducing self-reported PTSD symptoms in a population of veterans with MST, expanding on established literature that has demonstrated the effectiveness of CPT in treating PTSD related to sexual assault in civilian populations.