Usual chest radiographic findings in pulmonary tuberculosis are well described in radiologic literatures for both primary and postprimary phases of disease. Authors have evaluated 249 patients ho were admitted and newly proven to have adult-onset pulmonary tuberculosis at Chang-ang Univ. Hospital from January, 1985 to December, 1986. Unusual findings were noted in 76 of the 249 patients with adult-onset pulmonary tuberculosis. These unusual findings most frequently could be seen in 3rd decades and showed no sex difference in incidence. A broad spectrum of abnormal findings including usual and unusual abnormalities were produced by adult-onset pulmonary tuberculosis. The unusual radiographic findings were arbitrarily classified. Pleural effusion without parechymal disease, unusual location of infiltrate and atelectasis were ralatively common. Hilar and/or mediastinal lymphnode enlargement, cavity without parenchymal infiltrates, septic lung-like infiltrates, completely clear lu gs, miliary infiltrates, fibrocalcific scar-like infiltrates, masslike density and rheumatoid lung-like infiltrates were occasionally noted. Pneumothorax without parenchymal disease and bron chocutaneous fistula are. The recognition of these unusual findings could further improve the detection and diagnosis of adult-onset pulmonary tuberculosis.