PTH measurements 6 h after surgery may significantly predict postoperative hypoparathyroidism and hypocalcemia; definitive hypoparathyroidism developed only in the group of patients with postoperative PTH levels < 12 pg/mL (17 patients, 7%), suggesting that a PTH level of >12 pg/mL is associated with a low risk of postoperative symptomatic hypocalcemia and may allow, in principle, a safe patient discharge without calcium supplementation. This evidence concerns the gene PTH and hypoparathyroidism.