Hepatocyte growth factor (HGF) is a pleiotropic factor which activates cell proliferation, differentiation and migration of various cell types. Its action is mediated by a receptor, Met, endowed with tyrosine kinase activity, which activates a complex signalling cascade and mediates the diverse cell responses. Although HGF action has been first demonstrated on epithelial cells, HGF and Met receptor expression have also been described in the developing and adult mammalian brain. In the developing brain HGF and Met expression areas are coincident with the migratory paths of precursor cells. These data will be reviewed together with cell culture data, which directly support a role for HGF in precursor cell migration and neuron differentiation.