Patients with pulmonary tuberculosis treated in 4 sanatoria in Niigata prefecture during the period from 1941 to 1961 were followed up. Of 2,756 patients, 1,193 responded and sent us effective information. However, 1,224 did not come into contact because of changed and unknown adress, 326 did not respond, and 13 were omitted because of incomplete answers. Of 1,193 effective responders, 568 had been treated by artificial pneumothorax (the pneumothorax group), and 552 had been treated by the other measures than pneumothorax (the control group). There were 65 deaths in the pneumothorax, group, and 40 deaths in the control group. No deaths from chest malignancies were reported in the pneumothorax group, while 4 chest malignancies in the control. In this survey, no evidence of increased frequency of chest malignancies including leukemia following multiple fluoroscopies during artificial pneumothorax was detected.