Sputum smears of 116 cases in 55 pulmonary tuberculosis patients with the demonstration of acid-fast bacilli in sputum were retrospectively reviewed to investigate the cytologic diagnosis of pulmonary tuberculosis in sputum. Epithelioid cells, multinucleated giant cells of Langhans or nonspecific type, or necrotic materials of caseation or nonspecific nature were found in 40% of the cases, but in 60% of the cases, only nonspecific findings including squamous metaplasia were found. Only in 6% of the cases, the cytologic diagnosis of tuberculosis was possible with the findings of epithelioid cells and muitlnucleated giant cells in a necrotic background.