AIMS To analyse a series of cases of osteosarcoma of the jaw. METHODS AND RESULTS The study included 74 cases of osteosarcoma of the jaw. Their clinical, radiographic and histopathological features were analysed, and their frequency with respect to aggressive and malignant pathologies of the jaw was determined. Survival was assessed in 17 cases with available follow-up. Osteosarcoma of the jaw accounted for 10% of primary malignant and aggressive tumours of the jaw, and for 8% of all malignant lesions of the jaw, including metastatic and lymphoproliferative tumours. The mean age was 43 ± 18 years. Radiographic features varied greatly and were non-specific, with a predominance of mixed images. The dominant histological pattern was osteoblastic (48.4%), followed by chondroblastic (37.1%). The survival rate at 5 years was 68%. Females and patients with a predominantly chondroblastic pattern had lower survival rates. CONCLUSIONS Osteosarcoma of the jaw was the most frequent primary malignant tumour of the jaw. Female gender and a predominantly chondroblastic pattern may be associated with a worse prognosis.