T HE National Health Service Act of 1946 aimed at promoting establishment in England and Wales of a comprehensive health service, designed to secure improvement in the physical and mental health of the people ... and the prevention, diagnosis and treatment of illness. Treatment is freely available. The Service is financed by earmarked deductions from wages, employer contributions, taxation, and by charges for certain items. Charges are made for prescriptions (2s. Od., or 28 cents per item), dentures, eyeglasses, and other medical items. An initial charge of ?1, or $2.80, is made for dental treatment costing more than this. Children and expectant mothers are exempt from dental charges, and special arrangements are made to provide exemption from all charges in cases of financial hardship. Since the program began operation on July 5, 1948, the evolution na.tural in such a large-scale undertaking has brought changes in personnel and in the services provided by the Service as well as in the demands by the English people on some branches of the program. Recently the British Ministry of Health published summary data for England and Wales on the annual use made of services provided by the National Health Service and on personnel involved in the provision of services, together with some data on hospital service for the period 1949-60 (1, 2). To analyze what has been occurring, the material has been converted into annual rates per 1,000 population so that population growth could be eliminated as a factor in looking at the increased volume of services and need for additional personnel. The extent of changes in absolute numbers has been determined as well as changes in the rates per 1,000 population. The first measure of change is of interest in itself because it reflects both professional participation in the Service, and changes in patient use; the second measure shows the impact on the population. The tabulations of the Ministry of Health are discussed under seven headings, selected as most nearly conforming to the categories of health services familiar to us in the United States. In bending the material in this fashion it is recognized that the organizational structure of the National Health Service is no longer reflected in these data. Trends in the availability of facilities and personnel and in use of services were felt to be worth examining statistically at a time when the British approach to providing medical care is frequently being discussed. In the period from mid-1949 through mid1960 the population of England and Wales expanded by nearly 2 million, from 43,785,000 to 45,755,000. This expansion of 4.5 percent can be related meaningfully to the expansion in the absolute numbers of physicians, dentists, Mrs. Brewster is chief and Miss Seldowitz is a medical economist in the Health Economics Branch, Division of Community Health Services, Public Health Service.