Human immunodeficiency virus infection changes the clinical presentation of tuberculosis infection with atypical radiographs and more common extra-pulmonary involvement. We retrospectively studied pleural tuberculosis in HIV-positive patients over a 5-year period. We identified 70 patients with pleural tuberculosis by positive Mycobacterium tuberculosis cultures of pleural fluid and/or pleural tissue, including 43 HIV-positive and 27 HIV-negative patients. The HIV-positive patients were significantly younger (mean age, 38 +/- 1 years in HIV-positive vs 52 +/- 3 years in HIV-negative patients, p < 0.05). There were more intravenous drug abusers in the HIV-positive group (74 vs 30 percent, p < 0.01). The HIV-positive group had significantly fewer positive tuberculin skin tests (41 percent vs 76 percent, p < 0.03). Both groups had similar pleural fluid cellularity and pleural biopsy histologic conditions, but the HIV-positive patients demonstrated significantly more acid-fast bacteria identifiable in pleural tissue (69 percent vs 21 percent, p < 0.01), and a higher incidence of positive M tuberculosis cultures of sputum (53 percent vs 23 percent, p = 0.02). Pleural tuberculosis in HIV-positive patients presented more often as a manifestation of a greater burden of microorganisms and impaired host response.