The National Mental Health Association (NMHA) is our nation's only volunteer citizen movement whose mission encompasses all aspects of mental health and mental illness. Its mission is threefold: to promote mental health, to prevent mental illness, and to improve the care and treatment of persons with mental illness. All aspects of this mission include aspects of mental health prevention. Obviously, activities to promote mental health and to prevent mental illness are prevention activities. In the area of improved care and treatment of persons with mental illness, advocacy activities that can reduce the severity of an illness are considered preventive measures. This paper will explore the Mental Health Association's role in prevention, with focus on prevention efforts in Pennsylvania. These efforts may be undertaken by MHA volunteers or staff; most often they involve volunteer and staff collaboration.