Ewing's sarcoma is rarely found occurs in the bones of the hands and feet. We report a case of Ewing's sarcoma of the left calcaneus in a 15-year-old girl who complained of left heel pain and swelling. An open biopsy was performed and histological examination showed the proliferation of uniform small round cells. Immunohistochemical staining for CD99 showed diffuse strong positivity in the cytoplasmic membrane of the tumor cells. After preoperative chemotherapy, a below knee amputation was performed.