Quercetin, a typical flavonoid, possesses diverse biochemical and physiological actions, including antiplatelet, estrogenic, and anti-inflammatory properties. This review mainly centers on recent ten years findings with respect to intervening diabetes and its complications with the well-known flavonoid quercetin. After a short introduction of quercetin, major in vitro and in vivo findings are summarized showing that quercetin is a promising molecule for the treatment of these diseases. Finally, we contemplate future development and application prospects of quercetin. Despite the wealth of in animal research results suggesting the anti-diabetic and its complications potential of quercetin, its efficacy in diabetic human subjects is yet to be explored. The problem may become an important direction in the future research.