The authors describe studies showing the effectiveness of involuntary outpatient commitment in improving treatment compliance, reducing hospital readmission, and reducing episodes of violence among persons with severe psychiatric illnesses. They point out that because of its role in enhancing compliance with treatment, outpatient commitment can be regarded as a form of assisted treatment, such as assertive case management, representative payeeship, and mental health courts. The authors argue that such assisted treatment is necessary for persons with severe psychiatric illnesses who are noncompliant with their medication regimens because many lack awareness of their illnesses because of biologically based cognitive deficits. They recommend outpatient commitment for any individual with a severe psychiatric disorder who has impaired awareness of his or her illness and is at risk of becoming homeless, incarcerated, or violent or of committing suicide, and they provide case examples. The authors conclude by addressing eight of the most common objections to outpatient commitment by mental health professionals and civil liberties groups that oppose outpatient commitment.