This report was prepared for the Wisconsin State Legislative Council's Special Committee on Mental Health Issues. It summarizes legal issues and procedures relating to the admission, commitment, and treatment of the mentally ill in Wisconsin. Part I sets forth legal definitions of certain key mental health terms, including mental illness as it is defined generally and in relation to involuntary commitment, chronic mental illness, incompetence, and developmental disabilities. Part II describes legal concepts which provide the basis for the legal rights currently provided to the mentally ill. This section looks at constitutional rights concerned with liberty interest, least restrictive setting, procedural due process, humane conditions and minimally adequate treatment, refusal of treatment, and release. It also examines statutory rights related to conditions of confinement, periodic review of placement, and confidentiality. Part III provides a detailed description of the current standards and procedures which apply to obtaining voluntary and involuntary care and treatment for the mentally ill within the civil court system. Part IV provides a brief description of the current statutory procedures which apply to receiving mental health treatment within the criminal justice system. (NB)