Aims: To explore (1) the influence of pretreatment and treatment factors on treatment retention among a multi-ethnic sample of adolescents and (2) the potential differential influence of pretreatment and treatment factors on treatment retention within each ethnic subgroup. Participants: A multi-ethnic sample of 420 adolescent juvenile offenders in treatment for substance use problems (U.S.-born Hispanics n = 222; foreign-born Hispanics n = 94; African-Americans n = 66; and non-Hispanic Whites n = 38). Design: Cross-sectional data were examined using analysis of variance (ANOVA) testing putative differences in treatment retention for the entire sample (N = 420) for the following factors: (1) ethnicity, (2) psychiatric comorbidity, and (3) treatment variables. The second set of analyses examines differences in treatment retention associated with these factors within the ethnic subgroups. Finally, supplementary analyses were conducted to explore the potential influence on retention of the following cultural factors: (a) ethnic orientation, (b) perceived discrimination, and (c) acculturation level (for Hispanic youth only). Findings: Consistent with prior research, results indicated that non-Hispanic White adolescents had significantly higher treatment retention than the ethnic minority adolescents (p = 0.003). The particular factors related to treatment retention varied greatly across the four ethnic subgroups; however there were no differences in treatment retention by any of the cultural variables. Conclusions: Taken together, the results suggest that ethnic minority youth continue to drop out of treatment at higher rates than their non-Hispanic White counterparts, and the factors associated with treatment retention vary greatly across ethnic groups.