Fiberoptic bronchoscopy is a major tool in the diagnostic evaluation of pulmonary disease in patients with the Acquired Immune Deficiency Syndrome. Multiple opportunistic infections and Kaposi's sarcoma affect the lung in this disorder. In contrast to opportunistic infections, Kaposi's sarcoma is rarely reported to be diagnosed by means of bronchoscopy. This report describes five of seven patients in whom endobronchial lesions consistent with submucosal involvement by the tumor were seen, and Kaposi's sarcoma was diagnosed without complication. Kaposi's sarcoma must be considered in the differential diagnosis of pulmonary disease in patients with a proven extrapulmonary tumor focus, and fiberoptic bronchoscopy is the initial diagnostic procedure of choice. Endobronchial Kaposi's sarcoma may be a marker for parenchymal involvement by the tumor. Diagnosis of endobronchial Kaposi's sarcoma can be an important factor in decisions regarding therapy.