Efficient methods to introduce and express therapeutic genes in the central and peripheral nervous system will find applications in the treatment of neurodegenerative diseases caused by single gene mutations or degeneration with a mechanical, metabolic, or immunological origin. The goal of our research is to develop experimental gene therapy, based on in vivo gene delivery with viral vectors, to promote neuroregeneration in the peripheral and central nervous system. This paper provides an overview of work to determine the capacity of herpes simplex and adenoviral vectors, encoding members of the neurotrophin gene family or the intraneuronal growth-associated protein B-50/GAP-43, to stimulate neurite outgrowth. Initial results demonstrate that viral vector-mediated transfer of genes encoding these neurite growth promoting molecules could be an effective strategy to enhance the growth potential of injured neurons. A number of biological and technical hurdles that have to be settled in order to move closer to future clinical applications will be discussed briefly.