This study was done to compare the effect of ligation of inferior thyroid artery main trunk versus its individual branches on postoperative hypocalcaemia.60 patients with indication for different types of thyroidectomy were randomly allocated into two groups 30 patients each. Group one (30 patients) where the main trunk of inferior thyroid artery was ligated, while in group two (30 patients) the individual branches were ligated.Preoperative PTH and serum calcium were estimated for both groups, postoperative serum calcium was estimated on day 1 and day 6 postoperative, the PTH was estimated on day 1 postoperative in both groups.