In recent years provision of care for psychiatrically disturbed adolescents has received increasing attention. The present situation was summarized in a leading article in the British Medical Journal (1971) which emphasized one aspect of this provision—the need for adolescent in-patient facilities based within the community. This paper describes the ideas and practices of an adolescent unit which was opened at Hill End Hospital, St. Albans, in September 1969 to take younger adolescents (up to 16) of both sexes, from the area of the North-West Metropolitan Regional Hospital Board. This area covers 13,000 square miles and has a population of 4½ million, which the Unit aims to serve with 11 available beds. Who should be admitted to these places is clearly a critical question.