Sixty-seven patients with a pulmonary hemorrhage of more than 600 ml within 48 hours were studied. Mortality was primarily related to the rate of bleeding and exceeded 75% when the patient bled more than 600 ml within 16 hours. Surgical intervention in patients bleeding at this rate was associated with a mortality of 23%. Age of patient and extent of underlying pulmonary disease did not influence survival. These results emphasize the dangers inherent in overreliance on conservative management. Early surgery whenever possible is advocated.