During recent years it has been discussed whether mediastinoscopy could be replaced or supplemented by other diagnostic procedures for detection of mediastinal lymph node metastases in patients with pulmonary cancer. The results of 289 mediastinoscopies were analyzed and correlated to thoracotomy in order to evaluate the procedure. Two hundred and six males and 83 females were included in the study. The mean age was 63 years for men and 58 years for women. Mediastinoscopy was positive (N2 disease) in 113 cases (39%) and negative in 176 cases. The 113 N2 patients were not operated upon. One hundred and seven patients (37%) had thoracotomy performed. 12% of these patients had metastases at the time of thoracotomy. Mediastinoscopy is still the most reliable method in selecting patients with bronchogenic carcinoma for thoracotomy. It is important to make a careful dissection during the mediastinoscopy at both tracheo-bronchial angles as well as at the subcarinal. Eleven percent of the metastatic lymph nodes were found only at the subcarinal or at the contralateral tracheo-bronchial angle. Sixteen (5.5%) of the 289 patients are still alive, with a follow up of more than six years. Only resected patients survived.