Since the introduction of multimodality treatment, the prognosis of patients with high-grade non-metastatic osteosarcoma has significantly improved. A retrospective review was performed to assess the long-term results of this approach in a single centre setting, and to investigate the impact of potential clinical prognostic factors. Between 1985 and 1993, 35 patients with stage II-A and II-B osteosarcoma underwent preoperative chemotherapy (high-dose methotrexate), wide surgery, and adjuvant chemotherapy (cisplatin-doxorubicin/bleomycin-cyclophosphamide-dactinomycin) (modified T-10A protocol). There were 19 males and 16 females. Median patient age was 17 y (range 12–42). Primary tumour sites were the extremities (83%) and axial bones (17%). In spite of an unfavourable grade 3–4 histologic response rate to high-dose methotrexate of 12%, 31 (88%) patients were able to undergo limb-sparing surgery and 28 (80%) were rendered disease free after the planned therapy. Median follow-up was 8 y. The actuarial overall survival and disease-free survival rates were 64% and 49% at 5 y, and 59% and 49% at 10y, respectively. Tumour size and primary site were significant prognostic factors for survival in univariate analyses. In conclusion, long-term survival after combined modality treatment can be achieved in more than 60% of patients with localised osteosarcoma, including non-appendicular lesions. Limb-sparing surgery is a realistic goal for most cases. The prognostic value of tumour necrosis and the efficacy of neoadjuvant chemotherapy should be interpreted according to individual high-dose methotrexate scheduling.