Medical thoracoscopy (MT) for cases of exudative pleural effusion without a diagnosis by either clinical, radiological, laboratory or cytological investigation is performed as an established diagnostic method for the diagnosis of pleural diseases which has been performed routinely in many clinics. MT was done mainly with a rigid thoracoscope under mild sedation and local anesthesia in an endoscopy room with basic monitoring. It allows for the direct inspection of the pleural space and biopsies taken under direct vision. The diagnostic yield is in the order of 90-95% for malignant disease and can be as high as 100% for pleural tuberculosis. Additionally, MT can be performed for therapeutic as well as diagnostic purposes. Although MT remains an invasive procedure, complications are infrequently seen. Due to both the advantages of MT and the gradually increasing incidence of mesothelioma and malignant pleural disease, the use of MT for pleural effusions will be increasing in pulmonary clinics in coming years. Additionally MT will have some new developments; such as semirigid thoracoscopy, florescent or auto-florescent thoracoscopy, narrow-band imaging, thoracoscopy in patients without pleural effusion.