Recent advances in optics, video systems and endoscopic operating instruments have led to increasing application of thoracoscopic surgery, as it has become easier to perform and more accurate. We performed 586 video-assisted thoracic surgical procedures for diagnosis and treatment (May 1992-Dec. 1998) 127 were for diagnostic thoracoscopy and 79 for pleurodesis. 380 cases of operative thoracoscopy included pulmonary wedge resection (for interstitial lung disease, benign and malignant pulmonary tumors and pulmonary metastases) bullectomy, management of empyema, pleural tumor biopsy, thoracic sympathectomy, pericardial window formation, thoracic spinal procedures and resection of posterior mediastinal cysts. Recently we have had good experience in evacuating blood and blood clots from the thorax which accumulated after cardiac and thoracic surgery. Patients were placed in the lateral thoracotomy position and were ventilated with a double-lumen endotracheal tube, enabling collapse of the operated lung. The operating approach was through 1-3 thoracic ports. Mean operation time was 55 minutes, chest-tubes remained for 2.2 days (mean) and mean hospitalization was 3.3 days. There were no wound infections or significant postoperative complications. 5 patients had air leaks longer than 7 days; none required further surgical intervention. There was intercostal neuralgia and Horner's syndrome after thoracic sympathectomy (1 each) In cases in-which localizing the parenchymal lesion was difficult, the lung was palpated directly by inserting a finger through a small incision or a mini-thoracotomy. Conversion to thoracotomy was performed when primary malignancy of lung was diagnosed by frozen section. Only 2 patients had thoracotomy for uncontrolled bleeding. Thoracoscopy is a minimally invasive surgical technique with very low morbidity and high diagnostic accuracy. Postoperative recovery is brief and uneventful.