Six hundred and sixty-three patients with bronchial carcinoma underwent lung resection after mediastinoscopy had shown no apparent involvement of the mediastinal nodes. The average age was 65 years. Ninety-five percent of the patients could be followed up. A resectability rat of 97.3% was achieved. The operative mortality was 5.5%, irrespective of whether a lobe or whole lung was removed. The 5 year survival rate could be determined in 417 patients. Staging of the disease was done at the time of operation, which makes is possible to analyze the factors influencing survival. Mediastinal node involvement is associated with a high operative mortality and a very poor outlook after resection. Selection by routine preoperative mediastinoscopy has not improved the long-term survival rates as compared with other series in which such selection was not carried out. This confirms that the biological behavior of the tumor and not the initial selection determines the long-term survival. The prognosis is very grave with mediastinal node involvement.