The merge of cell therapy with gene therapy forms a more effective combined stem cell therapy/gene therapy. An introduction to combined stem cell therapy/gene therapy is made in this minireview briefly, including the often used cell types, vectors and their advantages and disadvantages. Examples of some diseases in human being or in animals which have been treated with combined stem cell therapy/gene therapy successfully are given also. It is pointed out that carcinogenesis might occur during the treatment and how to overcome such problems.