Younger age, tumor size, central compartment and bilateral lymph node dissection, extrathyroidal extension, and decrease in postoperative calcium levels were identified to be the factors associated with the risk of postoperative hypoparathyroidism. The risk of permanent hypoparathyroidism (PtHP) was found to be linked with older age, thyroiditis, extrathyroidal extension, and reduction in postoperative calcium levels.

• In this retrospective multicenter study, 326 pediatric patients who had thyroidectomy clustered into age groups (≤15 or > 15) were analyzed.

• Of participants, 36 (11.0%) developed postoperative hypoparathyroidism: 20 cases (6.13%) developed PtHP.

• More frequent occurrence of postoperative hypoparathyroidism was evident in younger patients, in larger tumors, in case of extrathyroidal extension, and in central compartment and bilateral lymph node dissection.

• More frequent development of PtHP was seen in older patients, in case of thyroiditis, and extrathyroidal extension.