This is a report of the "Health Sector Priorities Review" that the World Bank undertook with a number of collaborators, over two years. The core of this review is a series of studies on the public health significance of major clusters of diseases in the developing world and on the costs and effectiveness of currently available technologies for their prevention and case management. This analysis of TB, supported as a part of these studies, revealed the tremendous burden of TB and the existence of interventions of proven efficacy that were some of the most cost-effective in the international public health armamentarium.