Hydrothorax due to pleuroperitoneal communication is a rare complication in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). One of the problems of this complication is the need to cease CAPD, which means that the patient must shift completely to hemodialysis. Therefore, a quick, minimally invasive, and complete surgical repair of the pleuroperitoneal communication is required. We recently treated a patient who had developed a right hydrothorax soon after the introduction of CAPD. Clinical examination led to a diagnosis of pleuroperitoneal communication. The patient was successfully treated by complete thoracoscopic repair of the communication. We could precisely identify the defective site on the diaphragm using the dye-added CAPD solution method. CAPD was restarted 5 days after the operation, and there was no recurrence of hydrothorax after the operation.