Veterans who have experienced military sexual trauma (MST) report numerous psychosocial difficulties including sleep disturbance and posttraumatic stress disorder (PTSD). Cognitive Processing Therapy (CPT) has been shown to effectively reduce total PTSD symptoms among veterans with MST-related PTSD; however, sleep disturbance may persist after successful treatment. Sleep disturbance is associated with suicidal self-directed violence, substance use, and poorer physical health. Identification of if and when CPT can sufficiently address sleep disturbance may help to determine when adjunctive interventions may be indicated. The current study described the rate of sleep disturbance in a sample of veterans with MST-related PTSD before and after CPT. In an exploratory analysis, potential baseline predictors (i.e., sociodemographic, PTSD symptoms, trauma-related cognitions, depression, physical health) of change in sleep disturbance following CPT were assessed. A secondary analysis of 72 male and female veterans enrolled in a randomized clinical trial examining the efficacy of CPT for MST-related PTSD was conducted. Most veterans reported clinically significant sleep disturbance at baseline (100%) and post-treatment (89%). A significant relationship between clinically significant change in PTSD symptoms and resolution of sleep disturbance was not identified. Using hierarchical multiple linear regression, potential predictors of change in sleep severity following CPT were assessed; however, no significant predictors were identified in this exploratory analysis. These results are consistent with previous research describing high residual rates of sleep disturbance in veterans with PTSD, despite reductions in overall PTSD symptoms. Future research should focus on identifying effective augmentation strategies for CPT to specifically address sleep disturbance.