Human eryopreserved parathyroid autografts have been performed in six patients following reoperative parathyroid surgery. All patients were rendered hypoparathyroid by their most recent reoperation. Parathyroid tissue was successfully autotransplanted after as long as eighteen months of cryopreservation. Viability and expected in vivo function of cryopreserved parathyroid tissue may be predicted by in vitro testing of parathyroid hormone secretion in response to varying ambient calcium concentration. Parathyroid cryopreservation with subsequent autotransplantation is a practical solution to the problem of permanent hypoparathyroidism that may follow multiple surgical procedures for persistent hyperparathyroidism.