During the first half of the 20th century, thoracoscopy was applied in the management of pulmonary tuberculosis. After the discovery of the anti-tuberculous drugs, it was developed to a diagnostic tool for thoracic disorders. Thoracoscopy, as it is applied nowadays by pneumonologists, differs from thoracoscopic surgery (evolution and application of the technique in thoracic surgery) and concurrently has the advantage of being less invasive and cheaper, since it is performed under local anesthesia, in an endoscopy suite, using undisposable instruments. Due to its high diagnostic accuracy, it is the procedure of choice for undiagnosed pleural effusions, which is the main indication of this technique. It also gives the option of talc poudrage that is the procedure of choice for pleurodesis in malignant pleural effusions. Thoracoscopy encounters similar applications in the management of pneumothorax. It is a safe, effective and easy to learn method. As the interest for the technique and the number of the trained pneumonologists are continuously increasing, thoracoscopy is expected, within the next years, to find the position it merits in the diagnostic and therapeutic armamentarium of pneumonologists. Pneumon 2003, 17(1):29-38.