The aim of this retrospective analysis was to evaluate patient and tumor characteristics and treatment results and prognostic factors for patients with craniofacial osteosarcoma (CFOS). The COSS database was searched for patients with previously untreated, histologically confirmed craniofacial osteosarcoma with at least one follow-up examination. In a 28-year period extending from 1977 to 2004, 49 eligible patients were identified and their charts retrospectively analysed. The median age at diagnosis was 19.7 years (range: 4.6-57.2) with no gender predilection. Thirteen CFOS were second or even third primary malignancies. The jaws were the primary site in 27 patients (55% - mandible 15 (31%), maxilla 12 (24%)), while extragnathic bones were involved in 22 (45%). All 49 patients underwent surgery; in 37 (76%) combined with chemotherapy, in seven (14%) with chemotherapy and radiotherapy. Twenty-one patients (43%) received preoperative chemotherapy and the other 28 (57%) had primary surgery. A complete surgical remission was achieved in 32 patients, of whom 24 remained in local control. Actuarial five-year overall and event-free survival rates were 74% and 44%, respectively. Extragnathic site (p<.001) and documented postsurgical rest of the primary tumor (p<.001) were associated with inferior overall survival probabilities. All 24 patients who achieved and maintained local surgical control survived disease-free. Multidisciplinary treatment of CFOS within a multicenter setting resulted in long-term survival in well over two thirds of affected patients. Extragnathic sites and failure to achieve and maintain local surgical control emerged as strong negative prognostic factors.