Alcoholism is a frequent complication of methadone treatment and is one of the few behaviors found to correlate with methadone treatment failure. To eliminate drinking among severely alcoholic patients, we tested the efficacy of incorporating methadone into a behavioral contingency to reinforce disulfiram ingestion. Methadone was dispensed to alcoholic narcotic addicts contingent upon their ingesting disulfiram, and as a control patients were urged to take disulfiram but received methadone regardless of whether they took disulfiram. The results indicated that the reinforced disulfiram treatment was highly successful in controlling alcoholism. In addition, nonstatistically significant trends suggested that the reinforced disulfiram treatment resulted in a superior adjustment, as reflected in arrest rate, unemployment, and illicit drug use. There appeared to be no significant physiologic or behavioral adverse effects.