A five-year-old boy with Ewing sarcoma of the proximal femur was operated at our institution with limb-sparing surgery and biological reconstruction of the proximal femur with a vascularized fibular autograft. During this procedure, the proximal femur was soaked in liquid nitrogen which was subsequently fixed to the fibular autograft, while the epiphysis of the femoral head was spared. To the best of our knowledge, this is the first report of epiphysis-sparing surgery of the proximal femur via a vascularized fibular autograft surrounded by a liquid nitrogen-treated tumor bearing bone autograft. Three years postoperatively, the patient remains disease-free, has a full weight-bearing extremity with good function, and a remodeled proximal femur with minimal deformity. There are no radiological or clinical signs indicative of femoral head osteonecrosis. In conclusion, hip-sparing biological reconstruction is a successful method of limb preservation as an alternative to tumor endoprostheses.