Tuberculosis is one of the major infections affecting children worldwide. It causes significant morbidity and mortality, especially in infants and young children. Factors such as overcrowding, poverty and the HIV epidemic have all contributed to the resurgence of tuberculosis globally. The highest rates of tuberculosis occur in resource-poor countries and over the last decade case notifications in children have been increasing steadily, particularly in Sub-Saharan Africa. Mycobacterium tuberculosis infects millions of children worldwide every year, yet accurate information on the extent and distribution of disease in children is not available for most of the world. We describe some of the unique aspects of tuberculosis infection in children and review the epidemiology of disease in children worldwide.