Mycobacterial infections can be found in 10% of AIDS patients. Seventy cases with HIV+ infection were examined: they exhibited clear alterations of the chest and contemporaneous isolation and identification of mycobacteria. Primary tuberculosis is the most frequent manifestation in these patients. Alveolar parenchymal mono/bilateral infiltrates are the radiographic patterns of this pulmonary condition; they usually present without excavation (45.7%). Hilar and/or mediastinal lymph nodes are usually associated, and no pleural effusions. The main problem is the differential diagnosis with pneumocystis carinii pneumonia, especially the form involving lung apices. A correlation has been observed between the blood level of T-lymphocytes and their subsets (CD4 level) and the radiographic patterns of tuberculosis in AIDS patients. In fact, pleural effusion is frequent in patients with CD4 less than 200, while miliary nodules and cavitations are more frequent in the cases with CD4 greater than 200.