Acquired cystic kidney disease (ACKD) is a well-known complication of long-term hemodialysis. To the best of our knowledge, only six patients on continuous ambulatory peritoneal dialysis have been reported to develop this disease. We herein report two such cases, and concluded that the morphology of ACKD seems to be independent of the type of dialysis and that hemodialysis is not necessary for the development of ACKD.