We selected 95 patients with mediastinal adenopathy and no signs of goiter, myasthenia gravis or mediastinal involvement by other disease. All patients underwent, for screening purposes, transthoracic fine needle aspiration biopsy based on chest x-ray and CT findings. Patients were then subdivided into 4 groups. One group of 22 patients with prevalent anterior mass localization underwent anterior mediastinotomy. One group of 19 patients with prevalent middle mediastinal mass localization underwent cervical mediastinoscopy. Two other groups of 27 patients each with both anterior and middle mediastinum localization randomly underwent anterior mediastinotomy or mediastinoscopy. Fifty-one Hodgkin's and 44 non-Hodgkin's lymphomas were diagnosed in total. In 11 cases (11.57%), median sternotomy (2) or thoracotomy (9) were necessary for establishing the final diagnosis. The overall diagnostic accuracy was 80.43% for cervical mediastinoscopy and 95.91% for anterior mediastinotomy. The statistical analysis performed on all patients showed a significant difference (chi 2 = 5.56, P less than 0.025, df = 1) between the two procedures.