Rationale:Non-traumatic bilateral spontaneous massive renal hemorrhage confined to the subcapsular and perirenal space, also known as Wünderlich syndrome, can occur suddenly and insidiously and cause serious consequences if not properly identified and managed. We report a case of bilateral spontaneous massive renal hemorrhage in a series of devastating episodes.Patient concerns:A 38-year-old woman undergoing peritoneal dialysis for 7 years for end-stage renal disease presented with disturbances in consciousness and sudden hypotension.Diagnosis:The patient's laboratory results indicated an abrupt drop in hemoglobin level. Emergent abdominal computed tomography (CT) showed a rupture of the lower pore of the left kidney, with massive hemoretroperitoneum. A second sudden reduction in hemoglobin level occurred 2 months later during the same admission course, with poor response to urgent blood transfusion. Contrast extravasation at the lower pole of the right kidney and posterior pararenal space along with a subcapsular hematoma was revealed on abdominal CT.Intervention:The patient's initial episode was managed with emergent transcatheter arterial embolization (TAE) of the left renal artery and again after the second episode for occlusion of the inferior branches of the right renal artery.Outcomes:After the first episode, immediate postprocedural angiography showed total occlusion of the left renal artery without contrast extravasation. Follow-up CT performed 10 days after the first TAE showed a residual left perirenal hematoma that extended to the left retroperitoneal and left upper pelvic region, without active bleeding. No follow-up imaging was done after the second TAE except for immediate postprocedural angiography, which showed no additional contrast extravasation of the right renal artery.Lessons:Bilateral spontaneous massive renal hemorrhage is rare and generally occurs in patients undergoing dialysis. Known studies appear primarily in case reports. Most patients can be treated successfully with TAE when diagnosed early.