An increase in tuberculosis cases in the United States has been partially linked to the large number of patients with acquired immunodeficiency syndrome. Symptoms are indistinguishable from those of other opportunistic infections and include cough, low-grade fever, and weight loss. In patients with early human immunodeficiency virus (HIV) infection, radiographic findings resemble those seen in patients with reactivation tuberculosis. In patients with advanced HIV infection, chest radiographs typically reveal bilateral, symmetric, coarse, nodular densities. An upper lobe distribution is not prevalent. Lymphadenopathy is reported in many patients. Antituberculous therapy leads to clinical and radiographic improvement. Radiographic deterioration during therapy should suggest the presence of another opportunistic infection. Mycobacterium avium complex (MAC) infection of the lung cannot be distinguished from tuberculosis clinically or radiographically. Therapy, however, is less likely to be successful in patients with MAC infection.