ABSTRACT The osteosarcoma (OSA) is the most diagnosed primary bone cancer in canine patients. This work reports a case of a canine, six years old, mongrel, female, intact, with an OSA in the hard palate. Physical examination detected a firm mass in the palate. Thoracic radiographs, hematological and biochemical exams, histopathological exams and computed tomography were requested. A chondroblastic OSA was diagnosed and the tumor was characterized by immunohistochemistry. There was never evidence of metastasis in this case. The treatment consisted of the combination of conventional chemotherapy, metronomic chemotherapy, and palliative care, aiming at greater survival and well-being of the patient since surgical excision was not possible due to the location and extension of the tumor. Osteogenic sarcomas of the hard palate are rarely seen and described in the literature. In this article we present a characterization of the osteosarcoma with uncommon localization in the hard palate.