The liver in an adult healthy body maintains a balance between cell gain and cell loss. Though normally proliferatively quiescent, hepatocyte loss such as that caused by partial hepatectomy, uncomplicated by virus infection or inflammation, invokes a rapid regenerative response to restore liver mass. This restoration of moderate cell loss and 'wear and tear' renewal is largely achieved by hepatocyte self-replication. More severe liver injury can activate a potential stem cell compartment located within the intrahepatic biliary tree, giving rise to cords of bipotential, so-called, oval cells within the lobules that can differentiate into hepatocytes and biliary epithelial cells. A third population of stem cells with hepatic potential reside in the bone marrow; these haematopoietic stem cells can contribute to the albeit low renewal rate of hepatocytes, make a more significant contribution to regeneration and even completely restore normal function in a murine model of hereditary tyrosinaemia.