The course of tuberculosis mortality in the United States during the 4 years of the country's participation in the war was more encouraging than was anticipated at the beginning of the war. Despite unfavorable conditions of work and housing in some areas and the loss of a large number of physicians and nurses to the armed services, the tuberculosis death rate for the country not only continued to decline during the war years, but declined almost as rapidly as in the 4 years preceding the country's entrance into the war. Generally, economic conditions improved throughout the country during the war, with the expansion of industry and more widespread opportunity for employment. In addition, the threat of war led to intensified efforts for the control of tuberculosis on the part of local, State, and national health agencies, both official and voluntary. For the first time, funds were made available to the United States Public Health Service for an all-out attack on the tuberculosis problem, and, through the combined efforts of the Selective Service System, this agency, and local and State health organizations, case-finding by X-ray was carried out on a scale never before realized in this country. Tuberculosis, however, is a chronic disease, and continued progress toward its ultimate control depends upon continued effort. Today, there are in this country population groups and geographic areas in which the mortality from tuberculosis exceeds that in other groups and other areas by as large an amount as the tuberculosis death rate at the beginning of the century exceeds the present-day rate. As in the past, so in the present, mortality statistics are the signposts for the tuberculosis control program, directing efforts to the areas where the greatest problem lies. This paper, the third in a series of annual reports,2 presents data on the number of deaths and death rates for tuberculosis in the United States and in each State for 1945 with comparable data for the earlier war years, 1942-44, and the prewar period, 1939-41.