BACKGROUND: To evaluate the significance of increased of intraoperative parathyroid hormone(IOPTH) 10 min after parathyroidectomy in primary hyperparathyroidism. METHODS: All patients underwent parathyroidectomy were retrospectively included. Following the results of IOPTH, three groups were defined: Group 1: increased of IOPTH, Group 2: <
50 % decreased of IOPTH, and Group 3: >
50 % decreased of IOPTH. RESULTS: Unilateral approach was performed and shifted to bilateral neck exploration(BNE) when indicated. There were single adenoma, double adenomas, and hyperplasia in 84 %, 5 %, and 11 % of cases respectively. We noted that 100 %, 80 %, and 4 % of patients had a polyglandular diseases in Groups 1, 2, and 3 respectively. Double adenoma and hyperplasia were present in 55 %, and 45 %, 22 %, and 58 %, 1 %, and 3 % in Groups 1, 2, and 3 respectively. Female patients represented 55 %, 71 %, and 81 % of patients in Groups 1, 2, and 3 respectively. Cure rate was 99 %. CONCLUSIONS: Patients with increased of IOPTH level 10 min after parathyroidectomy had a polyglandular diseases in 100 % of cases and needed BNE.