A 63-year-old woman was found to have pathological fracture of the right lower tibia through a brown tumour, hypercalcemia, and a soft tissue mass at the lower pole of the right lobe of thyroid gland. US scan of the neck showed a well-circumscribed heterogeneously-hypoechoic mass with displacement of the right lobe of thyroid gland. Diagnosis of parathyroid adenoma was confirmed on histopathological examination of the excised specimen. The cause and clinical manifestations of primary hyperparathyroidism are discussed. Imaging methods of parathyroid gland are presented.