Spontaneous retroperitoneal hemorrhage (SRH) is a rare and potentially fatal condition. Acquired cystic kidney disease (ACKD) may cause SRH in hemodialysis patients. However, presentation of retroperitoneal hematoma as hemoperitoneum in peritoneal dialysis (PD) patients is exceedingly rare. We report a 44-year-old male PD patient who presented with hemoperitoneum secondary to retroperitoneal hematoma. The reason of SRH was rupture of the cysts of ACKD. The patient underwent unilateral nephrectomy with subsequent disappearance of hemoperitoneum. The importance of this case lies in the fact that the patients who have been receiving dialysis for a long time should be under surveillance in terms of ACKD development and potential associated complications such as cyst hemorrhage and malignancy.