Abstract Background: Microwave ablation (MWA) refers to all electromagnetic methods of inducing tumor destruction. Aim of Study: The aim of this study was to evaluate the outcome of ultrasound-guided microwave ablation of unre-sectable hepatocellular carcinoma using cold shaft antenna. Material and Methods: A total of 65 patients with Hepa-tocellular carcinboma (HCC) were referred to interventional Radiology Department for ablation of presumed non resectable tumor. The study group included 49 (75.4%) male and 16 (24.6%) female, with an average age (±SD) of 55±7.2 years (range, 48-72 years). Conventional gray scale ultrasound and triphasic computed tomography were performed for all patients before ablation. The microwave system used was HS AMICA (apparatus for microwave ablation, hospital service, Rome, Italy), with electronically controlled microwave generator. A 14 Gauage cooled shaft electrode named AMICA-probe was used to deliver microwave power to the liver tissue. The patients were then followed-up with contrast enhanced com-puted tomography (CT) and serum a-fetoprotein levels. Results: Among the 65 patients, complete ablation was achieved in 60 patients after initial treatment (92.3%). Initial complete ablation rates in patients with nodules <2cm, 2- 5cm, and >5cm were 100%, 92.1%, and 85.7% respectively. The probability of achieving a complete ablation was signif-icantly greater in patients with tumor size of <5cm. Conclusion: Sonographically guided MWA is an effective ablative method that can be applied in unresectable HCC of various sizes and different locations with reasonable safety.