The creation of the National Health Service is treated, analytically and historically, as a planning process involving major changes in the social organisation of health as a part of the larger set of social and economic reconstruction policies undertaken by the wartime Coalition and postwar Labour governments. Definitions of 'health' are considered as relative both to social expectations and ideology, and to theoretical models of the organisation of health services. These models are identified with certain socio-political agents or interests in the providing and consuming of health services: professional groups, public and private authorities, non-professional workers, and the public. The models of the health service advocates and of the medical profession are considered as reference points. A framework is presented for the analysis of the representation of these interests, by the state, in the planning and operation of the NHS, and as beneficiaries of its services. Through a detailed historical consideration of internal health service planning documents of the major interests, including the medical profession, the health service advocates representing the Labour party and trade unions, and recently released documents of the Ministry of Health and the Coalition and Labour Cabinets, the interaction of the interests with the two governments and with each other is traced, and the reconciliation by the state of the health service models proposed by them is analysed. It is argued that the changes wrought in the social organisation of health in Britain can be described according to certain principles of the organisation of pre- and post-NHS health services: principles of public access, structure of services, structure of administrative control and structure of planning representation. Tne major interests were represented differentially by the state with respect to each of these criteria; similarities and differences between the approaches of the two governments to the representation of interests are examined, and it is concluded that, although the health service advocates and the public benefited from a free and universal scheme, the public and non-professional health workers enjoyed considerably less representation than the medical profession in the particular services provided by the NHS and in its planning and administration.