In India, indigenous remedies have been used in the treatment of diabetes mellitus since the time of Charaka and Sushruta. Plants have always been an exemplary source of drugs and many of the currently available drugs have been derived directly or indirectly from them. The ethnobotanical information reports that about 800 plants may possess anti-diabetic potential. Out of several Indian medicinal plants 33 plants were reviewed. The most effective antidiabetic Indian medicinal plants are Acacia arabica, Aegle marmelose, Agrimonia eupatoria, Allium cepa, Allium sativum, Aloe vera, Azadirachta indica, Benincasa hispida, Beta vulgaris, Caesalpinia bonducella, Citrullus colocynthis, Coccinia indica, Eucalyptus globules, Ficus bengalenesis, Gymnema sylvestre, Hibiscus rosasinesis, Ipomoea batatas, Jatropha curcus, Mangifera indica, Momordica charantia, Morus alba, Mucuna pruriens, Ocimum sanctum, Pterocarpus marsupium, Punica granatum, Syzigium cumini, Tinospora cordifolia, Trigonella foenum graecum. A wide array of plant derived active principles representing numerous chemical compounds has demonstrated activity consistent with their possible use in the treatment of diabetes.