Background: Hepatocellular carcinoma (HCC) is the most common primary tumor of the liver. Traditional therapies might not be sufficient to eradicate total tumor because they target mainly the differentiated cells. Liver transplantation is a treatment method but donors are not easily available. Liver stem cell-targeted therapy is considered to increase the efficiency and safety of the treatment. Studies suggest that liver-specific stem cells might be involved in liver regeneration and liver carcinogenesis, but more researches are needed to confirm these facts. We designed this work to characterize and compare between in vitro cultured liver stem cells isolated from malignant and non-malignant tumor tissue over a period of a month. % CD133 expression was determined by flow cytometry. Our results showed a significant increase in CD133 expression in stem cells isolated from malignant liver tissues compared with those isolated from non-malignant liver tissues (p=0.0004). Interestingly, prolonged cultured stem cells isolated from malignant liver tissue were found to proliferate while those isolated from non-malignant liver were found to be differentiated. However, further studies are needed to elucidate the role of liver-specific stem cells in liver cancer development and recurrence