Between August 1975 and March 1981, 12 patients underwent forearm parathyroid autotransplantation with cryopreserved tissue following reoperative parathyroid surgery. Tissue had been cryopreserved two to 18 months. Follow-up ranged from four to 66 months (median, 18 months) following autotransplantation. All patients required calcium supplementation as a condition for autografting; six patients were no longer receiving calcium supplementation at most recent follow-up and in one patient the dosage was being tapered. The presence of a parathyroid hormone gradient of 2 : 1 or greater correlated well with freedom from calcium supplementation. Of seven patients with preautograft and postautograft urinary cyclic adenosine monophosphate (cAMP) determinations, three with increases following transplantation did not require calcium, three without increases continued to require calcium, and the patient whose dosage was being tapered had increased urinary cAMP levels.