Summary In a mental health service in which increasing emphasis is to be placed on community care, the arrangements made by local authorities need to be planned and maintained as a part of a comprehensive mental health service the components of which are dependent on each other. The Mental Health Act has given an opportunity for greater flexibility in providing the different form of community care based on individual need. The increased provision of training centres in a system of progressive and continuous social rehabilitation emphasises the need for accurate clinical diagnosis and social assessment. The provision of residential accommodation for different groups of mentally disordered persons is bound to introduce problems of selection. These may not be so troublesome as may be supposed. There is an increasing scope for preventive measures by local authorities, based on research in medical and social fields.