Although efficacious treatments, including Cognitive Processing Therapy (CPT), are available for treating Posttraumatic Stress Disorder (PTSD), a substantial number of clients do not receive a full course of CPT due to clients dropping out prematurely. Examining factors associated with treatment dropout may increase our understanding on how to tailor interventions to prevent treatment dropout. This study examined the relationship between early therapeutic alliance and
treatment dropout, and client age and pretreatment PTSD symptom severity as predictors of dropout and moderators of the alliance-dropout association. Clients were part of a larger randomized implementation trial, and either began CPT and dropped out (n = 38) or completed 12 sessions of CPT (n = 74). Results indicated early therapeutic alliance did not significantly predict treatment dropout, and age and PTSD severity were not significant predictors or moderators of the alliance-dropout association. Clinical implications of the findings are discussed.