Since hepatocellular carcinoma (HCC) is a hypervascular tumor in contrast with other hepatic tumors, it is important to measure hepatic blood flow in the diagnosis of HCC. Currently, contrast enhancement is required in the diagnosis of HCC by computed tomography (CT) as well as by ultrasonography (US). Levovist®, intravenously contrast medium for US that is currently available in Japan, is incorporated into Kupffer cells and sinusoids, and it is very helpful for the differential diagnosis and for the detection of localization of tumors as well as for assessment of blood flow. In addition, in treatments for HCC, contrast medium has been used for contrast enhancement during US-guided puncture and evaluation of treatment efficacy, leading to wider applications of contrast-enhanced US. Regarding the diagnosis of HCC by US, with contrast enhancement, one can not only visualize the specific vasculature and tumor staining but also measure hepatic blood flow, enabling grading of malignancy. Therefore, US is useful for the differential diagnosis of small nodular lesions. In this report, we discuss the importance of contrast-enhanced US for the diagnosis of typical HCC and nodular lesions with a size of 2 cm or less, as well as other types of HCC and HCC with blood vessel invasion. In addition, recent models of the US apparatus are equipped with new features such as three-dimensional imaging. We discuss potential new applications for contrast-enhanced US.