Background Total thyroidectomy for thyrotoxicosis is a difficult operation because of the high vascularity of the gland. It required a bloodless field for proper dissection and identification of important structure related to the gland. Patients and Methods From July 2012 till January 2016, 78 patients candidate for total thyroidectomy (TT) for thyrotoxicosis were enrolled. 39 patients with the use of harmonic scalpel (HS group) and 39 patients with the conventional hemostatic tie and knot technique with bipolar diathermy (CT group). Operations were done in the department of surgery at Ain Shams University hospitals. Results: The duration of surgery was significantly shorter in HS group (108 ± 15.7minutes) versus (152 ± 13.5minutes) in CT group (P<0.001). The amount of intraoperative blood loss was also significantly lower in HS group, being (65± 25.3ml) and (105.2 ± 26.4ml) in CT group (p =0.022) table 3. One patient in the HS group and two in CT group had transient recurrent nerve palsy (p=0.46). However, no patient developed a permanent recurrent paresis. One patient in the HS group and another one in CT group had transient hypocalcaemia (p=0.674). No other postoperative complication was noted. Conclusion Harmonic Scalpel reduced operative time and blood loss in thyrotoxic patients undergoing total thyroidectomy with no significance effect on recurrent nerve injury and transient hypocalcemia. Keywords Thyrotoxicosis. Harmonic scalpel. Hemostatic techniques. Total thyroidectomy.