Clients entering a therapeutic community (TC)–oriented drug treatment program were randomly assigned to day or residential conditions and interviewed at 2 weeks and 6 months after admission. Outcomes included Addiction Severity Index composite scores and summary scores for the Beck Depression Inventory, Symptom Checklist-90-R, and a social support scale. Only clients who remained in treatment for at least 2 weeks were included. The mean age of the sample (N = 261) was 32.9 (SD = 6.7 years) and the mean education level was 12.1 years (SD = 1.9 years); 30% were women. Comparison of outcome scores at 6 months between groups, while controlling for baseline values, indicated greater improvement for residential clients on social problems and psychiatric symptoms. The groups were similar on the 8 remaining outcomes, including measures of alcohol and drug problems. Overall, the level of improvement among day treatment clients was not significantly different from that of residential clients.