This study examined the relationship between racial/ethnic match and treatment outcomes for 224 women who participated in a clinical trial of group treatments for posttraumatic stress disorder (PTSD) and substance use disorders. Generalized estimating equations were used to examine the effect of client-therapist racial/ethnic match on outcomes. Results revealed racial/ethnic match was not significantly associated with session attendance. There was a significant three-way interaction between client race/ethnicity, baseline level of PTSD symptoms, and racial/ethnic match on PTSD outcomes. White clients, with severe PTSD symptoms at baseline, who attended treatment groups where they were matched with their therapist, had greater reductions in PTSD symptoms at follow-up than their counterparts who were racially/ethnically mismatched with their group therapist. Racial/ethnic match did not confer additional benefits for Black clients in terms of PTSD outcomes. Racial/ethnic match interacted with baseline substance use to differentially influence substance use outcomes at follow-up for all women. Clinical implications are discussed.