A 61-year-old female was diagnosed as having end-stage renal failure developed dyspnea soon after introduction of continuous ambulatory peritoneal dialysis (CAPD). Chest X-ray showed a right-side massive pleural effusion. Pleuro peritoneal communication was suspicious, because the hydrothorax significantly improved by the stop of CAPD. We performed video-assisted thoracic surgery. Using indigo carmine containing peritoneal dialysis fluid through a CAPD catheter, we found a fistula on the diaphragm from which blue dialysis solution flowed out like a fountain. The fistula of the diaphragm was directly closed with a surgical stapler and covered using cellulose oxidized (Surgicel) and fibrin glue. She could restart CAPD on postoperative days 7, and no recurrence of hydrothorax has been detected for 10 months after surgical treatment.