In Korea, radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) is most widely used under ultrasonography (US) guidance. With the technical development, small HCCs in challenging locations can be ablated effectively. Both fusion imaging and contrast-enhanced US is useful for identifying small inconspicuous HCCs on conventional US, thereby enable us to conduct successful RFA. Artificial ascites can enhance ultrasonic window and is helpful in avoiding thermal injury to the surrounding organs. Laparoscopy is also useful for guidance of RFA for subcapsular HCCs which are difficult to approach percutaneously. (J Liver Cancer 2014;14:89-96)