['The cost effectiveness of preoperative localization in cases of primary hyperpara-thyroidism has not been established. We analyzed the potential savings in operative time after localization with technetium 99m (99mTc) sestamibi scan.', 'Thirty-three patients had localization of a solitary adenoma with 99mTc-sestamibi. Measurement was made of the time required for adenomectomy, unilateral neck exploration (UNE), unilateral neck exploration and confirmation of one contralateral parathyroid gland (UNEC), or bilateral neck exploration (BNE).', 'The total operative time in minutes was 76.4 +/- 18.8 for adenomectomy; 87.5 +/- 20.4 for UNE; 105.6 +/- 25.0 for UNEC; and 117.9 +/- 26.7 for BNE. The time difference was significant between adenomectomy versus UNE, UNEC, and BNE. There were also significant time differences between UNE versus UNEC and BNE.'] Do analysis of savings in operative time for primary hyperparathyroidism using localization with technetium 99m sestamibi scan?