The aging immune system, while showing little in the way of quantitative changes, demonstrates important functional changes, especially T-cell functions. In addition to increased susceptibility to some infections, there is an increased likelihood of autoantibody production, and the emergence of monoclonal antibodies and other lymphoproliferative disorders. The role of the immune system in degenerative processes, and susceptibility to malignant processes requires further investigation. Biotechnology is producing many new methods of modulating immune function, with ever increasing specificity. Thus the future holds great promise for overcoming the effects of immunosenescence.