We collected 60 cases of parathyroid carcinoma, which was a rare disease of primary hyperparathyroidism, from 1980 to 1989, at several institutes in Japan by a questionnaire. The incidence of parathyroid carcinoma among the cases of the primary hyperparathyroidism in Japan was 4.8%, which was a little higher than that in the western countries. Most of the patients with parathyroid carcinoma show bone disease, high level of serum calcium and palpable anterior neck mass. Echogram is useful for the diagnosis of parathyroid carcinoma and its localization. Cure of the disease depends on the initial operation methods. En bloc resection of the tumor should be performed in each suspected case of a parathyroid carcinoma. The incidence of distant metastasis was 24%, and local recurrence 20% in Japan. Compared with the western countries, the lower incidence of local recurrence in Japan may be due to the operation method. The resection of local recurrence or distant metastases is effective for the control of recurrent hypercalcemia. We should always consider parathyroid carcinoma at the time of diagnosis and treatment of the patients with primary hyperparathyroidism.