SINCE the first successful pneumonectomy for carcinoma of the lung was performed by Graham in 1933, we have learned much about this common internal form of the disease. Reports have been appearing with considerable frequency in the recent surgical literature. The operability and curability rates have been steadily rising. There are indications that the almost prohibitive mortality rate of pneumonectomy is being rapidly lowered. Pulmonary physiology is better understood, and evaluation of patients is being carried out more thoroughly. Preoperative treatment and postoperative care have shown rapid advances, and surgical technic is at present more or less standardized. We believe that fluid balance after operation is an important factor in diminishing the incidence of postoperative cardiac failure. This has been the chief cause of mortality since penicillin has been reducing the number of our postoperative infections. It is our impression that we have previously overloaded the circulation of pneumonectomized patients