A survey was carried out of all patients admitted to New Zealand psychiatric hospitals over a 7-year period with a primary diagnosis of personality disorder. Despite a decrease in the total number of admissions, the relative totals for each personality disorder remained consistent. The personality categories differed significantly in terms of age, sex, marital status and committal status. These variables conformed closely to traditional clinical descriptions of the personality disorders, indicating that the reliability and utility of classical categorical systems may be greater than has been assumed in the literature. The DSM-III-R prototypical categories, which may possibly be a more natural representation of personality disorder syndromes, may be less useful than the traditional categories in clinical and research applications.