Parathyroid carcinoma is a very rare malignant tumor of the parathyroid gland. This cancer poses a great diagnostic and therapeutic difficulty due to its rarity and the absence of a characteristic clinical and paraclinical picture. The diagnosis is histological but is not always easy. Surgery remains the only curative treatment, and cervical radiotherapy can be discussed. Good prognostic factors are complete monobloc tumor resection, and bad prognostic factors are the presence of lymph node metastases at diagnosis, distant metastases, and nonsecreting carcinomas.