This chapter explores a population approach to identifying the needs of people in the community with severe enduring mental illness (SEMI). The chapter is based on a study carried out in general practice, which identified people with SEMI and the services they accessed. Several issues were highlighted that need to be considered when planning services for this client group. The author is a public health physician who has worked in several urban health districts and, throughout, has maintained an interest in the provision of services for people with mental health problems, especially in the community setting.