Methadone Transition Treatment (MTT) is a treatment program for opioid-addicted individuals that takes advantage of a 1989 change in federal guidelines permitting the establishment of 180-day detoxification programs. Thirty-eight subjects were assigned to either high-dose (80 mg) or low-dose (40 mg) methadone in a double-blind design. Both conditions showed initial dramatic decreases in illicit drug use and distress symptoms (opioid craving, withdrawal symptoms, and dysphoria). The high-dose condition showed a nonsignificant trend toward less frequent illicit drug use during the period of stable methadone dosing. We speculate that intensive psychosocial treatment, including weekly individual counseling and three-times a week group therapy, may have dampened outcome differences between high- and low-dose methadone conditions. Treatment retention was high for both dosage conditions.