The clinical manifestations, predisposing factors, and diagnostic approach to 29 young men and 35 elderly men with pulmonary tuberculosis admitted to a Veterans Administration hospital were compared. Elderly men had a higher number of underlying conditions such as atherosclerosis, previous gastrectomy, and malignancy, whereas alcoholism was more prevalent in the younger group. The classic symptoms and signs of tuberculosis were noted in a significantly higher proportion of the younger group: fever (62 percent versus 31 percent), weight loss (76 percent versus 34 percent), night sweats (48 percent versus 6 percent), sputum production (76 percent versus 48 percent), and hemoptysis (40 percent versus 17 percent) (p less than 0.05). Abnormal mentation was more common in the elderly group (31 percent versus 10 percent) (p less than 0.05). Radiographic findings were similar in both groups. Mortality related to tuberculosis was 20 percent in elderly men versus 3 percent in the younger men (p less than 0.05). Tuberculosis is frequently not considered in the differential diagnosis when elderly patients present with multiple medical problems and nonspecific complaints. Since there are differences in the clinical presentation and the outcome of pulmonary tuberculosis in elderly patients, a high index of suspicion for the disease should be maintained.