Parathyroid carcinoma is a rare entity with an 0,5-1% of incidence on primary hyperparathyroidism (HPP) in literature. The very high values of calcium and parathormone (PTH) and the clinical aspects of hypercalcemia are the characteristics findings in these patients. We present our experience on 6 pts on 153 cases with HPP treated (3,9%). The clinical and diagnostic suspects are frequently intraoperative findings and the decision making for the surgeon is not always easy (parathyroidectomy with or without hemithyroidectomy, lymphadenectomy, surgical resection of other tissues). The mortality rate is high and we have registered three deaths at 8,14 and 64 months.