Tuberculosis remains a health problem of extraordinary magnitude, especially in developing countries. Unfortunately, many of the same countries have the additional burden of a remarkably high prevalence of HIV infection. Because of the inherent capacity of tubercle bacilli to take advantage of deficiencies in cell-mediated immunity, tuberculosis has become an extremely important infectious complication of HIV disease in those developing countries in which the two infections coexist; the same is true, although to a lesser extent, in developed countries among those groups of patients with HIV infection in which there is also a high prevalence of remotely acquired tuberculosis. Prof. Chrétien helped call attention to the link between tuberculosis and HIV infection in France. Now, it is obvious that his cogent observations extend to much of the rest of the world.