The revolution in video technology has led to the acceptance of thoracoscopy as an important tool in thoracic surgery.A review of all patients undergoing thoracoscopy at the University of Maryland between November 1991 and March 1995 was performed to identify the incidence of intraoperative and postoperative complications. In addition, the role of computed tomography for predicting intraoperative complications was analyzed.Three hundred forty-eight procedures were performed in 321 patients. Twenty-seven patients required conversion to thoracotomy for various indications. In 12 patients further resection was required after frozen section diagnosis confirmed lung carcinoma. Six patients were opened due to adhesions. Two patients were opened due to inability to find the lesion (this represents 1.6% of all solitary pulmonary nodules). Three cases were converted to thoracotomy for lesions that were too large to remove (representing 2.5% of all solitary pulmonary nodules resected). Two patients required conversion to thoracotomy because of inability to obtain one-lung ventilation. One case required a limited thoracotomy for a lost needle used for needle localization of a solitary intraparenchymal nodule, and 1 patient had emergent exploration for bleeding. Early postoperative complications developed in 10 patients. There were two explorations in the immediate postoperative period for bleeding. Prolonged air leak occurred in 3 patients, empyema in 2, and recurrent pneumothorax, pulmonary edema, and pneumonia in 1 patient each. Computed tomography failed to diagnose adhesions in the majority of patients requiring conversion to thoracotomy.Thoracoscopy is a safe and effective procedure with low intraoperative and postoperative complication rates.