Naltrexone is a long-acting orally-administered opioid antagonist that has demonstrated clinical utility as an adjunct in the outpatient treatment of opioid abuse. Naltrexone can be administered on a daily, twice a week or three times a week regimen, based on the clinical needs of the patient, and the therapeutic goals of the patient and therapist. Because naltrexone is unscheduled under the Controlled Substances Act, any licensed physician can prescribe this drug. This decentralized therapeutic approach for the highly motivated patient permits a ready separation between the patient's drug using friends and his or her current activities. The patients most likely to benefit from naltrexone therapy are employed, married, stabilized on low-dose methadone prior to detoxification, or detoxified from their opioid dependency 7 or more days previously, and are highly motivated to be maintained on a nonopioid chemotherapeutic agent. Naltrexone does not cure dependency. It does assist clinicians in dealing with the medical, psychological and economic problems associated with primary opioid abuse. Naltrexone will work well only when it is part of a larger therapeutic regimen which is tailored to the individual needs of the patient.