Gene therapy (use of genes as medicines) is basically to correct defective genes responsible for genetic disorder by one of the following approaches. Gene therapy states and remains an experimental discipline and many researches remain to be performed before the treatment will realize its potential. He ideal design of a gene therapy strategy would first take into account the molecular basis of a disease process and then effectively tailor gene transfer techniques to mitigate toxicities and improve the effectiveness of existing therapies.. A gene therapy strategy modelled after the ADA protocol could play a role in delivering neuronal growth factors to the nervous system of patients with neurodegenerative disease. Cells from various tissues could be removed from a patient, be grown intissue culture where they could be stimulated to replicate, be genetically modified with retroviral vectors carrying a gene of therapeutic importance, and then be implanted into a brain with the intent to increase the local delivery of biologically active molecules. Genetic medicines are simple in concept, but challenging to make a therapeutic reality. We first outline thegeneral concepts that are applicable to genetic medicines. Gene therapy has the potential to eliminate and prevent hereditary diseases such as cystic fibrosis and is a possible cure for heart disease, AIDS and cancer. A gene therapy strategy known as viraldirected enzyme prodrug therapy has used retroviral vectors to eliminate some types of experimental brain tumorsin rodent model. Finally, from an ethics standpoint, it is important to consider whether medicine should surrender to the rule of technology or commit to a more responsible steering of the course of progress.