Medical plants play an important role in the management of diabetes mellitus especially in developing countries where resources are meager. This review presents the profiles of plants with hypoglycaemic properties, reported in the literature from 1990 to 2000. The profiles presented include information about the scientific name, family, methodology used, the degree of hypoglycaemic activity and the active agents. The large number of plants described in this review (176 species belonging to 84 families) clearly demonstrated the importance of herbal plants in the treatment of diabetes. It also shows the effort to isolate new potential antidiabetic agents. The plant families, including the species (sp), most studied for their confirmed hypoglycaemic effects include: Leguminoseae (11 sp), Lamiaceae (7 sp), Liliaceae (8 sp), Cucurbitaceae (7 sp), Asteraceae (6 sp), Moraceae (6 sp), Rosaceae (6 sp), Euphorbiaceae (5 sp) and Araliaceae (5 sp). The most studied species are: Citrullus colocynthis (Opuntia streptacantha Lem. (Cactaceae), Trigonella foenum greacum L. (Leguminosea), Momordica charantia L. (Cucurbitaceae), Ficus bengalensis L. (Moraceae), Polygala senega L. (Polygalaceae), and Gymnema sylvestre R. (Asclepiadaceae). Many studies have confirmed the benefits of medicinal plants with hypoglycaemic effects in the management of diabetes mellitus. The effects of these plants may delay the development of diabetic complications and correct the metabolic abnormalities. Moreover, during the past few years some of the new bioactive drugs isolated from hypoglycaemic plants showed antidiabetic activity with more efficacy than oral hypoglycaemic agents used in clinical therapy. (Int J Diabetes Metab 14: 1-25, 2006)