Seventy-four patients were included in this retrospective study and classified according to the newly devised classification based on clinical and imaging studies. The overall survival rate is 48%. The stage of the disease and the treatment, including chemotherapy, are the only prognostic factors significantly influencing survival. The survival of patients with osteosarcoma has improved with chemotherapy, but new therapeutic strategies should be found for different stages of disease. The authors' newly devised classification based on clinical and imaging studies proved to be adequate.