Giant Cell Granuloma is a rare bony lesion in the Head and Neck region. It mainly affects young adults between the age of 20 and 40. Occasionally, soft parts may be invaded, resulting from the direct effects of the parathyroid hormone. We report in this work the observation of a 36-year-old patient who presented for a maxillary tumor that revealed a parathyroid adenoma with associated hyperparathyroidism. The histopathological study of maxillary tumor’s material confirms the diagnostic of a giant cell granuloma.