The survival of patients with axial skeletal or pelvic osteosarcoma (OS) remains poor, and the management of these patients is challenging. The object of this study is a cohort of unselected patients aged < 19 years with primary high-grade pelvic/axial OS. Patients were treated with high-dose methotrexate, doxorubicin, cisplatin, ifosfamide followed or preceded by local treatment (surgery and/or radiotherapy). Twenty patients aged 3-19 years were treated. Eight patients had pelvic OS, 8 axial OS and 4 mandible/maxilla OS. All patients received chemotherapy, after which necrosis was evaluable in 9 patients (≥90 % in 3). Sixteen patients underwent surgery. Radiotherapy was administered to 8 patients (total dose 34-60 Gy). The median follow-up was 35 months (8-276), and the 5-year disease-free survival and overall survival rates were 37 and 40 %, respectively. Six patients were alive at the time of this report: 2 with pelvic OS (both responded well to chemotherapy, one underwent hemipelvectomy and the other had non-radical surgery plus radiotherapy); 1 with axial and multicentric OS (with a good histological response and radical surgery); 3 with mandible/maxilla OS. Two patients died of secondary tumors (one bone and one breast cancer). It is worth noting that 4 patients had a p53 mutation: 1 is alive, 2 died of their OS, 1 of breast cancer. Adequacy of local treatment and pathological response influenced the prognosis for axial OS, which remained dismal. A high incidence of p53 mutation emerged in our series of patients.