Background: Although they are expandable in vitro, hepatic progenitors are immature cells and share many immunomarkers with hepatocellular carcinoma, raising potential concerns regarding maltransformation after transplantation. This study investigated the effects of hepatic nuclear factor (HNF) 4 alpha on the proliferation, migration, and maltransformation of hepatic progenitors and determined the feasibility of using these manipulated cells for transplantation. Methods: The effects of HNF4 alpha on rat hepatic progenitors (i.e. hepatic oval cells) were analyzed by HNF4 alpha overexpression and HNF4 alpha shRNA. Nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice injured by carbon chloride (CCl4) were then transplanted with control, HNF4 alpha-overexpressing or HNF4 alpha-suppressing hepatic oval cells. Finally, the engraftment of these cells in the recipient liver was analyzed. Results: Rat hepatic progenitors (i.e. hepatic oval cells) expressed HNF4 alpha, although less than that in hepatocytes. When HNF4 alpha was overexpressed in these cells, the proliferation and migration of hepatic oval cells were reduced; but when HNF4 alpha was suppressed by shRNA, the proliferation and migration, and even anchorage-independent growth, of these cells were accelerated. RNA microarray and gene functional analysis revealed that suppressing HNF4 alpha not only impaired many biosynthesis and metabolism pathways of hepatocytes but also increased pathways for cancer. When transplanted into CCl4-injured NOD/SCID mice, few HNF4 alpha-suppressing hepatic oval cells localized into the liver, while control cells and HNF4 alpha-overexpressing cells engrafted into the liver and differentiated into albumin-positive hepatocytes. Interestingly, the hepatocytes derived from HNF4 alpha-overexpressing cells were less migrative and expressed less c-Myc than the cells derived from control cells. Conclusion: HNF4 alpha constrains proliferation, migration, and maltransformation of hepatic progenitors, and HNF4 alpha-overexpressing hepatic progenitors serve as an optimal candidate for cell transplantation.