This paper considers the elements that determine the health situation in any country: the specific hazards to health, the health services, and the general determinants which influence both the hazards and the services. The expectation of life--the best single measure of the health situation--is presented for each country of the Americas as representing the resultant of these determinants. The changing pattern of disease in the Americas--the emergence of noninfectious diseases as the major problems--is documented, and the need for epidemiologically oriented health planning is stressed. Data are presented to indicate that medical care is the least significant of the basic triad of public health, and that primary attention must be paid to both disease prevention and living standards.