A patient with a successfully treated primary osteosarcoma of the tibia experienced an isolated maxillary metastasis, which is an extremely rare entity. Once the tumor was confirmed histopathologically, a total maxillectomy and adjuvant chemoradiation therapy were carried out. There has been no local recurrence or distant metastasis for 1 year. A multimodality therapeutic approach is essential when these patients are treated. Surgery is the gold standard of treatment in operable cases. Adjuvant treatment is required to prevent local recurrence and distant metastasis.