Nine cases of pulmonary monosporosis treated in the Missouri State Chest Hospital over a period of 19 years (1956 to 1975) were reviewed. Nine other cases from the literature are summarized. Ten of these 18 patients underwent resectional operations with two operative deaths, one from respiratory insufficiency and the other from a bronchopleural fistula and massive hemorrhage. The rest of the patients had an uneventful recovery. The indications for resectional surgery are re-established for suitable cases. The underlying disease is the major determinant of the outcome of the surgery. Other modes of treatment are also discussed. Based on the analysis of these 18 cases, a guideline for the management of pulmonary monosporosis is proposed.