AbstractBackground.Parathyroid carcinoma is a rare entity, comprising fewer than 1% of cases of hyperparathyroidism. The disease generally presents with severe hyperparathyroidism and occasionally with vocal cord paralysis or a firm palpable cervical mass.Methods.The classic histopathologic features of trabecular pattern, mitotic figures, thick fibrous bands, and capsular and vascular invasion are not present in every case but are useful in assessing whether a particular hyperfunctional parathyroid lesion is a carcinoma. Nevertheless, recognition of malignancy at initial operation may be difficult. Management primarily involves complete surgical removal through en bloc resection, which may include adjacent central neck structures.Results.Adjuvant radiation therapy has not been proven to be uniformly effective, but several series show results suggestive of a possible survival advantage. Chemotherapy, genetic, and other biomodifying agents remain experimental. Long‐term outcome for this neoplasm remains problematic, and complications from intractable hypercalcemia constitute the foremost cause of death. Reported 5‐year survivals have ranged between 70% and 85%.Conclusions.Initial surgical success offers the greatest opportunity for cure. Reoperation for recurrence offers the potential for short‐ and intermediate‐term relief from the sequelae of hypercalcemia, but rarely results in cure. Severely elevated calcium levels should be controlled before initial surgery, and much of the treatment for recurrent or persistent disease, including reoperative surgery, is directed at control of hypercalcemia. © 2010 Wiley Periodicals, Inc. Head Neck, 2010