Two groups each of 10 patients enrolled in a 90-day outpatient detoxification program were classified on the basis of high (92.5% of tests) and low (7.5% of tests) rates of opiate-positive urine test results during two weeks of dosage stabilization. Pretreatment demographic variables did not differ between the two groups. Relapse to opiate use during the detoxification occurred in patients who were initially opiate free. By the end of the dose reduction period, opiate-positive rates were 60% and 87% of tests for the low and high opiate use groups, respectively. Sedative use and missed clinic days showed similar trends for both groups during the detoxification, although different patterns of drop-out from treatment were noted. Symptomatology increased during dose reduction for the low- but not for the high-frequency opiate group. In general, treatment outcome appeared equally poor for patients who showed low or high levels of illicit opiate drug use early in detoxification treatment.