In cancer and viral diseases, a great deal of research has focused on generating T-cell responses that might prove therapeutic. These efforts stem from our understanding of the immune system. It is known that the natural immune response can protect or suppress some viral infections and it is hoped that a potent T-cell mediated immune response might also be harnessed to fight cancer. Immunotherapy is a particularly attractive candidate therapy for the treatment of metastatic cancer because of the immune systems capacity for body wide surveillance. Since the generation of T cell clones is a laborious task and it is often impossible to derive T cell clones of the desired specificity and function from many individuals, especially in a timely fashion required for therapeutic interventions, T-cell receptor (TCR) gene transfer has a lot of appeal. TCR gene transfer seeks to transfer the antigen specificity of a T cell clone to other T cells. This article will review the last 15 years of research in TCR gene transfer since the first successful TCR gene transfer experiment, and seeks to give an insight into the areas of investigation currently being pursued to improve on current results and move TCR gene transfer into the clinic.