Mangifera indica Linn. (Anacardiaceae) is commonly called mango or ‘Mamuang’ in Thai. In ethnomedical systems, M. indica leaves have been used for the treatment of fever, diarrhea, fainting, abnormality of lymph node, and diabetes. Phytochemical screening of M. indica leaves showed the presence of flavonoids, tannins, alkaloids, terpenoids, anthraquinones, saponins, cardiac glycosides, and steroids. Mangiferin has been regarded as its major compound. Several biological properties of M. indica leaves such as anti-inflammatory, antioxidant, hypoglycemic, and hypolipidemic activities were reported. This review focuses on the traditional usage accompanied with pharmacological activities involving diabetes treatment such as antioxidant and antidiabetic activity of M. indica leaves. This information would be useful for phytopharmaceutical product development as an adjuvant therapy to diabetes treatment.