Hepatocyte transplantation has shown potential as an additional treatment modality for certain diseases of the liver. To date, patients with liver-based metabolic disorders or acute liver failure have undergone hepatocyte transplantation in several centers around the world. Results from individual patients are promising, especially for the treatment of liver-based metabolic disorders, but the lack of controlled trials makes the interpretation of the findings difficult. The current source of isolated hepatocytes is donor organs that are unused or deemed unsuitable for liver transplantation. Hence the major challenge that this field is facing is the limited supply of donor organs that can provide good quality cells. Alternative sources of cells, including stem cells, are under investigation. This Review discusses the current bench-to-bedside issues and future challenges that need to be faced to allow the wider application of hepatocyte transplantation.