We compared the effectiveness, safety, and costs of outpatient (n = 87) and inpatient (n = 77) detoxification from alcohol in a randomized, prospective trial involving 164 male veterans of low socioeconomic status. The outpatients were evaluated medically and psychiatrically and then were prescribed decreasing doses of oxazepam on the basis of daily clinic visits. The inpatient program combined comprehensive psychiatric and medical evaluation, detoxification with oxazepam, and the initiation of rehabilitation treatment. The mean duration of treatment was significantly shorter for outpatients (6.5 days) than for inpatients (9.2 days). On the other hand, significantly more inpatients (95 percent) than outpatient (72 percent) completed detoxification. There were no serious medical complications in either group. Outcome evaluations completed at one and six months for 93 and 85 percent of the patients, respectively, showed substantial improvement in both groups at both follow-up periods. At one month there were fewer alcohol-related problems among inpatients and fewer medical problems among outpatients. However, no group differences were found at the six-month follow-up, nor were differences found in the subsequent use of other alcoholism-treatment services. Costs were substantially greater for inpatients ($3,319 to $3,665 per patient) than for outpatients ($175 to $388). We conclude that outpatient medical detoxification is an effective, safe, and low-cost treatment for patients with mid-to-moderate symptoms of alcohol withdrawal.