Since September 2000, Community and Mental Health Department Faculty of Nursing University of Indonesia, have developed Professional Nursing Practice Model (PNPM) on Psychiatric Nursing at Dr. H. Marzoeki Mahdi Health Hospital. PNPM at Marzoeki Mahdi Hospital is the first PNPM especially for mental health. The study was a quantitative cross sectional study conducted during the period February 4th to July 30th 2001 and covering 79 client. The aim of the study was to identify characteristics of clients at PNPM. It was found that most of the clients were males, aged 20-55 years, living in the area of Jabotabek (Jakarta, Bogor, Tangerang and Bekasi), especially in Bogor, the city of the hospital. Most of them had no job, with a senior high school education whereas the number with unmarried status was nearly the same with the number with married status and belonged to the Sundanese ethnic group. Characteristics of the family were mostly as followed: big family, with more than 2 children, closed communication and family meeting during meals. On health status it was found that clients were admitted to the hospital because of angry/violence, angry/violence and talking/laughing by themselves, whereas the number of clients in the group never nursed in a hospital before were nearly the same as the number in the group ever nursed before, with average length of staying in hospital 9 days. It was revealed that the problem of hallucination was mostly found among the nursing problems. Health education was mostly on efforts to eliminate paranoid problems and Activity Group Therapy was focused on efforts to socialize the clients. The medical diagnosis of most of the clients was paranoid schizophrenia. It was concluded that in this study characteristics of the clients in PNPM was very varied. For optimal nursing criteria of clients at PNPM who should be admitted should be established.