The authors examined predictors of cocaine group treatment outcome in methadone maintenance treatment (MMT) patients, including cocaine urinalysis at intake and demographic variables. Clinic policy is that patients identified as using cocaine must attend a weekly cocaine-focused, cognitive-behavioral therapy (CBT) group. Cocaine treatment is based on a behavioral (escape) contingency model whereby completers must attend group-counseling sessions and produce cocaine-negative urinalysis results. Among the 113 patients enrolled in the cocaine group, 43 (38%) were treatment completers (who attended 6 consecutive weeks of group and produced 6 consecutive weeks of cocaine-free urine tests) and 70 (62%) were treatment noncompleters. Treatment completion (i.e., cocaine abstinence) was significantly associated with baseline cocaine-free urinalysis and higher methadone dose.