There is a pressing need to enhance the availability and quality of mental health services provided to persons from historically disadvantaged racial and ethnic groups. Many previous authors have advocated that traditional mental health treatments be modified to better match clients' cultural contexts. Numerous studies evaluating culturally adapted interventions have appeared, and the present study used meta-analytic methodology to summarize these data. Across 76 studies the resulting random effects weighted average effect size was d = .45, indicating a moderately strong benefit of culturally adapted interventions. Interventions targeted to a specific cultural group were four times more effective than interventions provided to groups consisting of clients from a variety of cultural backgrounds. Interventions conducted in clients' native language (if other than English) were twice as effective as interventions conducted in English. Recommendations are provided for improving the study of outcomes associated with mental health interventions adapted to the cultural context of the client. (PsycINFO Database Record (c) 2010 APA, all rights reserved).