Although osteosarcoma is the most common primary malignant tumour of bone, osteosarcomas of jaw are rare. In osteosarcomas of jaw, evaluating the clinicopathological factors affecting the prognosis is not easy because of different approaches to diagnosis, treatment, and follow-up. This study reviewed 14 cases of JOS that were diagnosed between 1990-2010, in terms of age, gender, site, clinical history, histopathologic type and histopathologic grade, treatment, and prognosis. Median age was 35 years, while male: female ratio was 1.8:1. Eight tumours were located in the mandible. Osteoblastic differentiation was the predominant feature in seven cases followed by chondroid osteosarcoma (four cases), fibroblastic osteosarcoma, low-grade (parosteal) osteosarcoma associated with fibrous dysplasia, and postradiation osteosarcoma (one cases each). During follow-up, recurrence was seen in four patients at least once and they all died. In conclusion, early diagnosis and complete resection seems to be effective in prognosis. Therefore, clinicians and pathologists should be aware of its characteristics and main differential diagnosis to avoid late recognition.