The study compares the sociodemographic and diagnostic characteristics of patients committed to psychiatric care in New Zealand in 1984 with total admissions and with the general population. Committed patients were significantly more likely to be aged 20-39 years, male, of Maori or Pacific Island ethnicity, and have a diagnosis of schizophrenia or affective disorder. These findings provide a baseline from which we may assess changes in the committed patient population following reform of the Mental Health Act.