Between April 1992 and April 1993, we performed fifty-four mediastinal biopsies in 51 patients with a mediastinal mass. Nine of these had lung cancer with mediastinal lymphadenopathy, and the remaining 42 had various primary mediastinal lesions. We have performed twenty video-assisted thoracic surgical procedure, twenty-six mediastinoscopies, and eight anterior mediastinotomies. In 3 patients the diagnosis was not obtained by mediastinoscopy, and video-assisted thoracoscopy was performed. We conclude that mediastinoscopy is indicated for the majority of lesions involving the peritracheal space. Restaging of lymphoma and highly infiltrative lesions are better managed by video-assisted thoracic surgery. Anterior mediastinotomy is indicated when feasible under local anesthesia for tumors infiltrating the anterior chest wall. In all other cases video-assisted thoracic surgery is preferable because it allows removal of large tissue biopsy specimens and even resection with wide surgical exposure and low operative trauma.