Gene therapy offers an elegant alteative to toxic chemotherapy regimens, mostly without severe side effects.Cancer gene therapy was among the first applications. Following the enthusiasm in the early nineties, a more rationale view is the recent way to look at it. This tutorial review looks upon the tools of gene therapy and the principle elements (vector, promoter, targeting, therapeutic gene). The principles of gene therapy such as gene directed enzyme prodrug therapy (GDEPT)and gene directed tumor vaccination are explained. Further, published protocols and clinical studies for pancreatic carcinoma gene therapy are reviewed. Finally, an outlook is given on the latest developments, some of them beyond conventional gene therapy.