Pleural effusions are seen relatively common in end-stage renal disease (ESRD) patients, on the other hand, hydrothorax secondary to pleuroperitoneal leak in continuous ambulatory peritoneal dialysis (CAPD) patients is rare. Since treatment modalities differ widely from that of other causes of pleural effusion seen in CAPD patients such as uremia, volume overload, congestive heart failure, infection and malignancy, pleuroperitoneal leak should always be kept in mind in the differential diagnosis and should be excluded urgently. To draw attention to this point, in this paper, 2 children on CAPD who developed a hydrothorax secondary to a pleuroperitoneal communication are presented with an overview of diagnostic tools and treatment modalities.