In childhood tuberculosis, it is possible to clearly distinguish among three basic stages: exposure, infection, and disease. The incidence of tuberculosis in children is low compared with that in adults, but latent infection is a major concern because children, who are exposed to Mycobacterium tuberculosis especially early in childhood, are at increased risk of developing the disease. Younger children particularly infants have a high relative risk of miliary or meningeal disease. The clinical manifestations of childhood tuberculosis differ noticeably from those of the disease seen in adults. Adolescents with tuberculosis have different demographic and clinical features from those of adults or children. Tuberculosis in adolescents has become relatively more important as the incidence of infection in childhood has decreased.