Support groups often help families cope more effectively with relatives' mental illnesses. This study examines the differences between support groups led by professionals and those led by family members, focusing specifically on group participation benefits and group content. Results indicate that participants of both professional and family-led groups reported that the groups provided them with needed information about mental illness and its treatment and that the groups improved their relationships with their ill relatives. Professional-led groups placed a greater emphasis on the relatives' problems and coping with emotions, and family-led groups placed a greater emphasis on advocacy. Suggestions are provided regarding increased collaboration between professional and family-led support groups.