Overall, the findings indicate that the various pretreatment and treatment factors measured in relation to treatment retention varied in their influence according to ethnic subgroup. In turn, this suggests that the influence of the various factors on treatment retention is related to cultural factors specific to the ethnic groups examined; however, for the cultural factors examined (ethnic orientation, perceived discrimination, and assimilation level for Hispanic youth), there were no differences in treatment retention. Consistent with previous research, the study found that non-Hispanic White adolescents had significantly higher treatment retention than ethnic minority adolescents. Particular factors related to treatment retention varied significantly across the four ethnic subgroups (U.S. born Hispanics, foreign-born Hispanics, African-Americans, and non-Hispanic Whites). In addition to ethnicity, level of mental disorders, particularly conduct disorder was linked with treatment retention among foreign-born Hispanics. Although having no choice in treatment type, being placed on a waiting list, and being legally pressured into treatment were associated with lower retention in treatment in the full sample, in the ethnic-specific analyses these factors remained linked to treatment retention for only certain ethnic subgroups. The 420 juvenile offenders in treatment for substance use problems consisted of 222 U.S.-born Hispanics, 94 foreign-born Hispanics, 66 African-Americans, and 38 non-Hispanic Whites. Variables measured for the entire sample were ethnicity, mental disorders, and treatment variables. The second set of analyses examined differences in treatment retention linked with these factors for each ethnic subgroup. Supplementary analyses were conducted to explore the potential influence on treatment retention of the cultural factors. 2 tables, 1 figure, and 57 references