The average survival of 620 deceased males with lung cancer irrespective of type of treatment was 7.39 months, of the deceased female patients, 6.89 months. The survival time was calculated from the day of surgery or from the last day of the first treatment series. Eighty-two per cent of the males and 80.4 per cent of the females died during the first year. Although attempts have been made to predict the rate of growth of malignant tumors, considerable variation exists in the rate of growth of primary lung carcinomas in individual patients. On the basis of the survival data of untreated lung cancer patients (average survival time of approximately 3.5 months), radiation therapy should be recommended to patients with lung cancer because of the improvement in survival time and the palliative effect on the patient following its use. Roentgenographic findings of lung cancer may be present long before the patient has any clinical symptoms. The development of a high index of suspicion for lung cancer in all physicians participating in the diagnosis of chest diseases should be encouraged. It is possible to cure a small percentage of patients with lung cancer by radiation therapy; a higher percentage of patients with operable lesions are cured by surgery used either singly or in combination with radiation therapy. Excellent palliation is obtained in approximately 65 per cent of the patients following the use of radiation therapy. The use of chemotherapeutic agents has little clinical value in lung cancer therapy.