Continuous cyclical peritoneal dialysis (CCPD) is a well-established, effective method of maintenance dialysis in patients with end-stage renal disease (ESRD). Massive hydrothorax producing hemodynamic compromise (tension hydrothorax) has been documented as an infrequent complication of both acute temporary peritoneal dialysis and continuous ambulatory peritoneal dialysis (CAPD). We recently saw a patient with massive hydrothorax as a consequence of CCPD. The etiology of this rare condition is thought to be that of a diaphragmatic defect with a one-way valve mechanism. Diagnosis is made by aspiration of the pleural fluid and estimation of pleural fluid glucose. Management of these patients requires pleural drainage and changing to hemodialysis if possible.