Surgical procedures of pleural cavity are crucial to complete the diagnoses or planning treatment of pleural effusions with an unknown aetiology. Traditionally, the transthoracic approach has been the most used procedure to study the pleural cavity. The subxiphoid video-thoracoscopy is becoming an alternative to the transthoracic approach. Subxiphoid video-thoracoscopy is a minimally invasive technique that allows us to study both pleural cavities with a single subxiphoid incision. In the supine decubitus, through a small subxiphoid incision, a rigid video-mediastinoscope is introduced. Once all the tissues are dissected, mediastinal pleura can be identified and incised. A 30° thoracoscopy is then inserted into the pleural cavity through the video-mediastinoscope to obtain samples of pleural fluid and biopsies of the parietal pleura and lung nodules if present. Subxiphoid approach has some advantages compared with the traditional transthoracic approach. On the one hand, contrary to traditional thoracoscopy, in subxiphoid video-thoracoscopy it is not necessary to do a transthoracic approach even for the insertion of a chest tube. Avoidance of intercostal ports probably decreases the risk of post-operative pain and the patients can be discharged 24 hours after surgery with no increase in surgical risk. On the other hand, we can explore both pleural cavities at the same time through a single incision, in case of bilateral pleural effusion. If malignancy is confirmed by frozen-section or by macroscopic evidence of intrapleural tumour infiltration or implants, a pleurodesis to avoid recurrence can be performed prior to tube insertion and closure.