A six-month-old child with a history of coarctation of aorta repair admitted to our hospital with recoarctation. She underwent cardiac catheterization for stent placement via right femoral access. Reportedly, there was difficulty inserting and removing the sheath. There was no bleeding or hematoma and the distal pulse well felt at the completion of the procedure. While in recovery unit child acutely deteriorated with tachycardia, oxygen desaturation, and hypotension. She was then endotracheally intubated and started on fluid resuscitation and on vasopressors infusion. Upon arrival to the pediatric intensive care unit (PICU) child was tachycardic, pale and noted a mass on the right lower quadrant of the abdomen. Her hemoglobin dropped from 12 gm/dL to 5 gm/dL. Given the child with hemorrhagic shock, and with right lower quadrant abdominal mass, a possibility of retroperitoneal hematoma (RPH) was considered. Other possible causes of hemorrhagic shock, such as vascular access site bleeding, pleural and pericardial effusions were ruled out.