Background Increasing evidence suggests that culturally and linguistically responsive programs may improve substance abuse treatment outcomes among Latinos. However, little is known about whether individual practices or culturally and linguistically responsive contexts support efforts by first-time Latino clients to successfully complete mandated treatment. Methods We analyzed client and program data from publicly funded treatment programs contracted through the criminal justice system in California. A sample of 5,150 first-time Latino clients nested within 48 treatment programs was analyzed using multilevel logistic regressions. Results Outpatient treatment, homelessness, and a high frequency of drug use at intake were associated with decreased odds of treatment completion among Latinos. Programs that routinely offered a culturally and linguistically responsive practice—namely, Spanish-language translation—were associated with increased odds of completion of mandated treatment. Conclusions These preliminary findings suggest that concrete practices such as offering Spanish translation improve treatment adherence within a population that is at high risk of treatment dropout.