The discovery of nitric oxide (NO) as a major signaling molecule in a number of pathophysiological processes . vasodilation, immune response, platelet aggregation, wound repair, and cancer biology - has led to the development of various exogeneous NO delivery systems. However, the development of ideal delivery system for human body application is still left as a challenge due to its high reactivity and short half-life in physiological condition. In this article, an overview of several nano-structures as potential NO delivery system will be presented, along with their recent research results and biomedical applications. Nano-size delivery system has immense advantages compared to others due to its high surface-to-volume ratio and capability for surface modification; thus, it has been proven to be effective in delivering nitric oxide with enhanced performance. Through this novel nano-structure delivery system, we are expecting to achieve sustained release of nitric oxide within adequate range of concentration, which ensures desired drug effects at the target site. Among different nano-structures, in particular, nanoparticle, microemulsion and nanofilm will be reviewed and compared to each other in respect of nitric oxide release profile. The proposed nano-structures for exogeneous NO delivery have a biological significance in that it can be further utilized in diverse biomedical fields as a highly promising therapeutic method.