Self-help groups for mental health problems are widely used, yet studies of their effectiveness show mixed results and are often not theoretically guided. Drawing on empowerment, stigma, and social selection perspectives, we test a theoretically organized model of the relationships between self-help group involvement, empowerment, and recovery outcomes (symptoms and quality of life). Using two-wave survey data from a sample of 553 persons with mental illnesses in self-help groups and outpatient services, we find (1) social selection' effects - persons with greater symptoms and lower quality of life are less likely to be a part of self-help groups, (2) that self-help is associated with some beneficial effects on self-esteem, but is associated with stronger beliefs about expected stigma, (3) that self-help may yield only slight benefits to quality of life, and (4) perceived helpfulness of self-help and group involvement are reciprocally related. Open-ended questions reveal why some of our respondents never attended self-help group meetings, why those who continue to attend do so, and why others stop attending.