Forty patients with malignant pulmonary disease underwent evaluation, staging, and a biopsy or resection by means of video-assisted thoracic surgery. There were 20 men and 20 women whose ages ranged from 27 to 82 years. Eight patients had a wedge resection for metastatic carcinoma, three a lobectomy for primary carcinoma, six exploration of the thorax, five biopsy of the aortopulmonary window, and eighteen a sublobar resection for primary carcinoma of the lung. There was no mortality. Three patients had air leaks that lasted an average of 8 days. Video-assisted thoracic surgery seems to be useful for more precise staging of carcinoma of the lung, and, in some patients, resectional operations can be performed.