: Primary hyperparathyroidism (PHPT) in pregnancy is rare and may be associated with increased maternal and fetal morbidity and mortality. The ideal timing for parathyroidectomy is during the second trimester, and parathyroidectomy in the third trimester is extremely rare. We present a case of a 32-year-old woman who was admitted to our hospital with severe hypercalcemia in the 36th week of her first pregnancy. Conventional bilateral neck exploration was performed and parathyroid adenoma was removed. The surgical procedure was tolerated well by the mother, and she delivered a healthy girl 10 days after surgery. The newborn had mild hypocalcemia that required minimal substitution postnatally; however, no tetany occurred. This case demonstrates that parathyroidectomy in the third trimester followed by spontaneous delivery may be performed safely.