Primary hyperparathyroidism is a systemic disease due to the disorders of calcium, phosphorus, and metabolic bone caused by the synthesis and hyper secretion of parathyroid hormone, which is characterized by hypercalcemia, hypophosphatemia, kidney stones, bone lesions, etc. The progression of PHPT is slow and it is not easy to find. At the same time, the clinical manifestations of PHPT are diverse and lack specificity. More importantly, the lesions of the jaw bone are rare, so it is easily misdiagnosed in the clinical practice. A case that the primary hyperparathyroidismis misdiagnosed as malignant neoplasm of mandible is reported in this paper.