This study examines the utility of several process-of-care performance measures (initiation, engagement, retention, and monitoring of drug use during treatment) as predictors of methamphetamine (MA) use outcomes at 12- and 36-month follow-ups. MA-dependent individuals (n = 871) participated in a randomized, controlled trial of outpatient psychosocial treatment from 1999-2002 and completed 12- and 36-month follow-up interviews. This sample included a treatment-as-usual group (n = 436) and a 16-week Matrix treatment (n = 435) group. Significant associations were observed between select process-of-care measures and MA use outcomes at both follow-ups. While correlational analyses showed an association between MA abstinence at follow-up and enhanced treatment engagement and retention, mixed logistic regression analyses indicated that sustained abstinence from MA during outpatient treatment was the strongest predictor of testing negative for MA use at both follow-ups. Results suggest that monitoring client drug use during treatment may be a useful process-of-care measure with MA-dependent users.