Fibrosis is a common end stage for a variety of liver diseases, including most chronic liver diseases, and results from an imbalance between collagen deposition and degradation. Mesenchymal stem cells (MSCs) have the ability to migrate into fibrotic livers and differentiate into hepatocytes. Hepatocyte growth factor (HGF) has potent anti-apoptotic and mitogenic effects on hepatocytes during liver injury and plays an essential role in the development and regeneration of the liver. In this study, human HGF-overexpressing human umbilical cord blood-derived MSCs (hHGF-HUCB-MSCs) were prepared using the pMEX Expression System, and the upregulation of hHGF expression was confirmed by RT-PCR and ELISA. HGF expressed by hHGF-HUCB-MSCs exerted a stimulatory effect on hepatocyte proliferation in vitro. hHGF-HUCB-MSCs were transplanted to investigate the therapeutic effects of these cells on carbon tetrachloride (CCL4)-induced liver fibrosis in a rat model. After 4 weeks of cell treatment once per week with 2 × 106 cells, biochemical analysis of the serum and histopathological analysis of the liver tissue were performed. The results of the biochemical analysis of the serum show that the hHGF-HUCB-MSC-treated group had higher levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase, indicating the improvement of liver function. Histopathology showed that the hHGF-HUCB-MSC-treated group had reduction in the density of collagen fibres. Thus hHGF-HUCB-MSCs can enhance liver regeneration and could be useful for the treatment of patients with liver fibrosis or cirrhosis.