Globally, diabetes causes about 1.5 million deaths per year. Data predicts that the current global epidemiological burden of diabetes is increasing alongside its long-term life threatening sequelae and side-effects from synthetic antidiabetic drugs. Challenges in the public healthcare delivery system, inadequate human and financial resources, expensive antidiabetic drugs coupled with their limited availability, efficacy and tolerability, and a higher priority for subventions to the control of communicable diseases such as HIV/AIDS than to drugs for non-communicable conditions especially diabetes have opened new vistas for diabetics to seek complementary and alternative medicines. As a corollary, there is a renewed momentum backed by the World Health Organization to discover newer, cheaper and better antidiabetic agents from medicinal plants. As data on putative antidiabetic properties of plants remain scattered, this review provides a new synthesis of antidiabetic plants from Africa, Central America, Mexico, South Asia, and Iran. In the countries mentioned in this review, numerous plant species decrease blood sugar levels by inhibiting the enzymes α-amylase and α-glucosidase. Other antidiabetic plants restore pancreatic cells, improve insulin secretion and sensitivity, decrease metabolic syndrome in type 2 diabetes patients in addition to exerting antioxidant and hepatoprotective functions. Mechanisms of action are mediated by phytochemical agents including saponins, polyphenols, ellagitannins, triterpenes, and elements such as Mg, P, Ca, K, Mn, Cu, Zn, S, Cr, Co, Ni and V. These plant compounds and elements may be included into new and more efficacious herbal drugs and nutraceuticals to lessen the global burden of diabetes.