This report discusses a rare case of giant cell-rich osteosarcoma. The patient, a 19-year-old male, was diagnosed with a metadiaphyseal osteolytic lesion when he consulted a local doctor complaining of motion pain without swelling. Radiography revealed a geographic osteolytic lesion, cortical thinning and ballooning without obvious cortical destruction. However, a fine onion skin-like periosteal reaction was observed on the lateral side of the femur. The transitional none was narrow and endosteal scalloping was also noted. Needle biopsied material clearly showed nuclear atypism of the stromal tumor cells with numerous osteoclast-like giant cells. Using a combination of pathological examination, radiography, computed tomography (CT) and magnetic resonance imaging (MRI), a diagnosis of giant cell-rich osteosarcoma was reached. After chemotherapy, resection and limb salvage surgery with an autogeneous autoclaved bone graft, a vascularized fibular graft were performed, and the patient has shown excellent limb function without local recurrence or distant metastasis during the past 72 months.