Basic fibroblast growth factor (bFGF), a heparin-binding mitogen for mesoderm-derived cells, also acts as a mitogen, differentiation inducing and maintenance factor for many neuroectodermal cells including glial cells, neurons, paraneurons, and their tumor counterparts. The molecule is expressed in several types of neuroectodermal cells in vitro and in vivo. Furthermore, bFGF occurs in many neuronal target tissues, and can prevent ontogenetic as well as lesion-induced neuron death. Thus, in terms of its wide range of functions, bFGF is apparently more than a ‘classical’ neurotrophic factor. Some of its essential features, such as regulation of expression, local availability and transport in the nervous system remain to be studied.