Two patients on continuous ambulatory peritoneal dialysis (CAPD) developed right massive hydrothorax and were diagnosed as having pleuroperitoneal communication. Thoracoscopic surgery and pleurodesis were performed. It showed that one was caused by multiple flaws in the diaphragm and that the other was attributable to multiple blebs in the diaphragmatic dome. After the procedure, both of them had no recurrence of hydrothorax and underwent CAPD safely. We recommend thoracoscopic surgery and pleurodesis as the first choice of therapeutic methods for pleuroperitoneal communication.