Worldwide, cancer remains one of the major causes of mortality. For example, American epidemiologists have projected that for 1996 nearly 550,000 USA patients will die - up from 310,000 in 1970. Furthermore, some 40 percent of Americans will eventually be stricken with the disease, and more than one in five will die of it. While this trend remains the same for developed countries, the situation is worse in developing countries. Although with chemotherapy, radiotherapy and surgery it is often possible to reduce the tumor burden dramatically, regrowth from residual cells is depressingly common, and the disease eventually becomes resistant to all standard forms of therapy, which is reflected by the fact that the survival rate has not improved during the last 20 years. Hence, it is hoped that new, simple, sensitive and specific methodologies will help to reduce the cancer incidence and, within this context, gene therapy has been heralded for its potential to revolutionize modern medicine through the use of recombinant DNA technology, in the search for cancer treatment solutions. A review of the different strategies employed in gene therapy and the analysis of more promising areas of development in gene therapy is represented.