In patients with recurrent malignant or benign pleural effusion practitioners use specific treatments, but they are then faced with the problem of pleural fluid recurrence. Several techniques of pleurodesis have been used, including drainage, surgery, intrapleural injections and poudrage. From an analysis of the results obtained and from our own experience, we have come to the conclusion that poudrage under thoracoscopy is the best type of pleurodesis.