Gene therapy has offered highly possible promises for treatment of cancers, as many potential therapeutic genes involved in regulation of molecular processes may be introduced by gene transfer, which can arrest angiogenesis, tumor growth, invasion, metastasis, and/or can stimulate the immune response against tumors. Therefore, viral and non-viral gene delivery systems have been developed to establish an ideal delivery vector for cancer gene therapy over the past several years. Among the currently developed virus vectors, the adeno-associated virus (AAV) vector is considered as one of those that are closest to the ideal vector mainly for genetic diseases due to the following prominent features; the lack of pathogenicity and toxicity, ability to infect dividing and non-dividing cells of various tissue origins, a very low host immune response and long-term expression. Particularly, the most important attribute of AAV vectors is their safety profile in clinical trials ranging from CF to Parkinson's disease. Although adenovirus and several other oncolytic viruses have been more frequently used to develop cancer gene therapy, AAV also has many critical properties to be exploited for a cancer gene delivery vector. In this review, we will briefly summarize the basic biology of AAV and then mainly focus on recent progresses on AAV vector development and AAV-mediated therapeutic vectors for cancer gene therapy.