Hepatocellular carcinoma is the most common primary malignancy of the liver in adults. It is also the fifth most common solid cancer worldwide and the third leading cause of cancer-related death. Recent research supports that liver cancer is a disease of adult stem cells. From the models of experimental hepatocarcinogenesis, there may be at least three distinct cell lineages with progenitor properties susceptible to neoplastic transformation. Identification of specific cell surface markers for each of the liver cell types, production of corresponding monoclonal antibodies and cell sorting techniques have together revolutionized the characteristics of normal stem cells. In hepatocarcinogenesis, multiple signaling transduction pathways, important for stem cell proliferation and differentiations, are deregulated. Strategies are being developed to identify and characterize the liver cancer stem cells. Targeting liver cancer stem cells may bring hope to curing hepatocellular carcinoma.