Findings indicate that the effects of religious behavior (measured by church attendance) at follow-up differs for White and Black clients. African-American clients reported higher levels of church attendance than did White clients. Controlling for church attendance at intake and the other treatment-related variables, church attendance was found to have a significant effect on Black clients' desistance from drug use. However, church attendance at 12-month follow-up was not a significant predictor of White clients' recovery from substance abuse. Findings suggest that religious involvement is especially influential on Black clients' recovery from substance abuse. Findings of this study should provide some insights for race-specific treatment interventions. Data were collected from intake and 12-month follow-up interview of 2,977 clients of the Drug Abuse Treatment Outcome Study (DATOS) in 11 U.S. cities from 1991 to 1993. Tables and references