This review summarizes the functional aspects, cellular kinetics and molecular mechanisms related to liver regeneration. Liver regeneration is a model of regenerative growth of tissues in adult animals. Rapid biochemical and gene expression changes following initiation of regeneration are mediated by specific stimuli, including growth factors and cytokines. The whole process involves multiple feedback loops between same or different types of cells. The end result is restoration of hepatic mass and preservation of the normal histology of the liver. All of this complex phenomenology occurs while the liver continues to provide all the metabolic support required to sustain life of the organism.