The current trend in health policies in Sweden is based on a holistic view of health and this means an increased overall responsibility for the county councils. There will be new challenges for the primary health care services, especially concerning epidemiology and health education. The community diagnosis model, which has three levels—namely the descriptive, analytical, and health action programmes—should prove to be a useful tool in this work. This article gives a general review and outlines the theoretical background of community diagnosis as a tool in broad preventive programmes at the local level. Skaraborg is the only county in Sweden that has a broad preventive programme, or health plan. This is based on a political decision taken in 1971. Experience of cooperation between primary health care and the Community Health Unit, at the county level during the seventies has provided the practical foundation for the community diagnosis model. The knowledge made available by the community diagnosis is of great value to the district physician in his daily work. When he knows more about the highly prevalent diseases (such as diabetes and hypertension) in the local community, he can better organize the treatment of these diseases in the health care centre. A knowledge of health risks, individual or environmental can, in the same way, facilitate his participation in the dialogue with members of the community and the planning of preventive measures.