摘要篇首： Pleural effusions, the excessive accumulations of fluid in pleural space, are frequently associated with a variety of clinical diseases, such as cancer, tuberculosis,pneumonia, etc.1,2 This means that both malignant and benign diseases can cause pleural effusions. Therefore, it is essential for clinicians to determine the etiology prior to the treatment of patients with pleural effusions.Whereas certain pleural fluid tests are helpful for the differential diagnosis, they usually give rise to low accuracy. In recent years, early detection approaches have been developed to timely recognize pleural effusions.Thoracoscopy is still one of such widely employed approaches for surgical detection of unknown origin of pleural effusions. Most importantly, it allows physicians to directly observe lesions, perform biopsies, and conduct necessary therapies. Moreover, the introduction of thoracoscopy3 amplifies the function of conventional thoracoscopy. Thus, thoracoscopy is an extremely useful tool for diagnosis and treatment of benign and malignant pleural effusions,4,5 especially in the developing counties.