From 1990 to 1999, three patients with non-tuberculous mycobacteriosis and 14 patients of tuberculosis underwent pulmonary resection in the National Sanatorium Ehime Hospital. Of the patients with tuberculosis, two were multiple drug-resistant cases and twelve cases were suspected of lung cancer before diagnostic resection. All three patients with non-tuberculous mycobacteriosis were symptomatic, had chest cavities in the lung, and were sputum-culture positive. There were no operative death in all patients, and one case of post-operative complication. Two patients, one with non-tuberculous mycobacteriosis and another with tuberculosis, failed in sputum negative conversion. The former had been treated for a long time preoperatively. Early resection in patients of pulmonary non-tuberculous mycobacteriosis and of pulmonary multiple drug-resistant tuberculosis is recommended to prevent further progression of pulmonary lesions.