Parathyroid carcinoma is one of the rare causes of primary hyperparathyroidism. These tumors account for 0.4-1% of all cases of primary hyperparathyroidism and it is difficult to distinguish from benign disorders of parathyroid glands. A 61-year-old female patient previously operated for parathyroid adenoma admitted to our clinic with parathyroid carcinoma suspicion. Clinical examination revealed a mass in the right half of the thyroid gland and radiological investigation supported the diagnosis. She underwent surgery and thyroidectomy, parathyroidectomy, neck dissection and strap muscle excision were performed. The pathological investigation revealed parathyroid carcinoma. The patient was discharged uneventful with oral calcitriol and calcium replacement.