ABSTRACT Objective:This prospective study was designed to evaluate the feasibility and outcome of thyroidectomy using Ultrasonically Activated Scalpel (UAS) in comparison to the conventional thyroidectomy Patients and Methods: This study comprised 40 patients with mean age 41.4+9 years, divided into two groups: Group A comprised 25 patients underwent thyroidectomy using UAS and 15 patients underwent conventional thyi oidectomy (Group B) Both groups were compared as regards operating time, operative blood loss (=weight of wet sponges-weight of dry sponges), postoperative seroma formation and surgeons' satisfaction regarding the ease of dissection, need of blood vessel ligation and dryness of the surgical field. Results: Mean operative time was significantly shorter in group A (77±5 8 minutes) compared to group B, (105.7±6.5 minutes) especially in cases with primary thyrotoxicosis and cancer thyroid. Intraoperative blood loss showed a significant (P