Gene therapy remains a new and exciting therapy that holds the potential to impact the care of many diseases. Cancer gene therapy strategies encompass a major part of this developing field. Initial preclinical and phase I clinical trials have demonstrated the ability to transfer genetic material to cells in vitro and in vivo with resultant expression of biologically active protein. Most of these studies have involved direct injection or local installation of vector. A majority of patients succumbing to cancer do so because of metastatic disease. Clearly, to broaden the impact of cancer gene therapy on these patients' outcome, new strategies for targeting regional or systemic disease are required. This article offers a review of current vectors and therapeutic strategies along with the application of these in human cancers.