Diabetes is a growing health concern worldwide and now emerging as an epidemic world over. The management of diabetes is still a major challenge. Thus there is great demand for research on natural products with anti-diabetic properties. Numerous studies have confirmed the benefits of medicinal plants with anti-hyperglycemic effects in the management of diabetes mellitus. In this review, we address the beneficial effects of selective medicinal plant species such as Allium cepa, Allium sativum, Aloe vera, Azadirachta indica, Gymnema sylvestre, Syzygium cumini and Pterocarpus marsupium, and emphasize on the role of active biomolecules which possess anti-diabetic activity.