The clinical records and tissue specimens of 20 patients referred to Anderson Hospital for treatment of osteosarcoma of the jaws were reviewed. Nine of the tumors arose in the maxilla and eleven in the mandible. Two were parosteal osteogenic sarcomas, one arising in the maxilla and one in the mandible; two osteosarcomas of the maxilla arose in areas previously irradiated for other conditions. No previous histories of trauma, benign tumors of the jaws, or Paget's disease of bone were noted. The most common presenting symptom in the series was a tumor or swelling of the affected area. The average age of onset of osteosarcoma of the jaw is one or two decades later than the age of onset of osteosarcomas of other locations. Roentgenographic examination is helpful, especially when an osteoblastic lesion is found in the bone. Only one case with widening of the periodontal membrane space was recorded. A histologic examination is imperative for a definitive diagnosis. Surgical resection is the recommended treatment for osteosarcoma of the jaws. Parosteal osteogenic sarcoma of the jaws has a better prognosis than osteosarcoma, since there is less tendency to metastasize. Among osteosarcomas of the jaws, the mandibular sarcomas have the best prognosis.