MEDIASTINOSCOPY as it is used today was first described by Carlens in 1959.1He reported a series of 100 cases of proven or suspected bronchogenic carcinoma in which mediastinoscopy was used primarily to evaluate pulmonary resectability. Palva in 1964 described the evolution and development of the technique and discussed an extensive application of mediastinoscopy to a wide variety of diseases affecting the mediastinum, such as bronchogenic carcinoma, sarcoidosis, mediastinal cysts, and primary tumors of the mediastinum.2Ward has recently published a series of 25 patients in whom mediastinoscopy was performed under local anesthesia with very satisfactory results.3 The greatest contribution of mediastinoscopy to date seems to be in determining the extent of the spread of bronchogenic carcinoma and thereby the feasibility of pulmonary resection. In cases of mediastinal lymph node involvement by bronchogenic carcinoma, nonresectability may be determined without subjecting the patient to a thoracotomy and the