This brief report describes an unusual complication of femoral venous access placement. A 17-year-old male underwent cardiopulmonary transplantation for complex congenital heart disease, which was complicated by thrombotic thrombocytopenic purpura, quadrilateral limb gangrene, and stroke. In an effort to urgently obtain a venous access, a right femoral venous catheter was placed into the right groin in the cardiac care unit. The patient subsequently experienced severe hypotension and abdominal distension. Ultrasound and CT scans of the abdomen demonstrated a large retroperitoneal hematoma. Aggressive resuscitation failed to stabilize the patient. Angiography demonstrated an unusual bleeding source from an arterial collateral circulation in the right side of the pelvis, which was then successfully treated with embolization.