We report hyperacute resorption of the femoral head within six weeks after triple corticosteroid injections. A 65-year-old male patient had bilateral idiopathic osteonecrosis proven by magnetic resonance imaging, and the unilateral pain was controlled with three separate corticosteroid injections. The clinical progression deteriorated, so the patient was transferred to our hospital six weeks later. The imaging studies and blood tests showed a destructive femoral head as well as bone marrow changes in the ipsilateral distal femur. The patient reported severe pain in the hip joint, and a cementless total hip arthroplasty was conducted. The postoperative histopathological findings revealed osteonecrosis of the femoral head and the distal femur. The authors found the rapid destruction of the femoral head by corticosteroid injections in osteonecrosis. We report these very rare findings along with literature reviews.