The reported incidence of postoperative hypoparathyroidism varies from 3% to 32%, and many surgeons are reluctant to perform a total thyroidectomy because of the risk of permanent damage to the parathyroid glands. We prospectively studied three groups of patients for evidence of acute parathyroid damage: group A consisted of 29 patients with total thyroidectomies; group B, 21 controls with partial thyroidectomies; and group C, 29 patients with total thyroidectomies that had been performed several months to years earlier. Functional status of the glands was measured by serum parathormone, calcium, and phosphorus levels. Although these levels fell postoperatively, they remained within normal limits. None of the long-term follow-up patients (group C) was found to have hypoparathyroidism, leading us to conclude that this risk may be overstated in the literature.