Diabetes Mellitus is one of the common metabolic disorders characterized by persistent hyperglycemia caused by absolute or relative insulin deficiency, causing abnormalities of carbohydrates, proteins & lipid metabolism and significant & significant disturbance of water, electrolytes. According to WHO the worldwide prevalence of Diabetes mellitus was estimated to be 422 million in 2014 and is projected to rise up to 750 million by the year 2030.Oral hypoglycaemic agents like sulphonylureas & bigunanides are still the major players in the management of the disease but there is growing interest in herbal remedies due to the side effects associated with oral hypoglycaemic agents. Unani Physicians were very much familiar to the symptoms and complication of the disease. Ibne Sina in his book Al Qanoon has described about the symptoms like polydipsia, polyuria and mentioned gangrene among its complication. The Unani herbal medicine have been the highly esteemed source of medicine throughout human history. Unani System of Medicine deals with several means of treatment like Ilaj bil Ghiza (dietotherapy), Ilaj bil Dawa (Pharmacotherapy) & Ilaj bil Tadbeer (Regimenal Therapy), that can be aided as an adjuvant therapies. Where as in Classical Unani literature recommendations of diets & exercise along with various compound formulations and single drugs are being used from ancient time such as Safoofe Ziabetus, Qurs Ziabetus Khas, Qurs Tabasheer, Safoofe Hindi, & Kachnar (Bauhina variegata), Gilo (Tinospora cordifolia), Tukhme Methi or Hulbah (Trigonella foenum-graecum), Klaonji (Nigella sativa), Tukhme Hyat (Witania coagulans), Tukhme Karela (Momordica charantia), Gurmar Booti (Gymnemma sylvester), Talhab (Spirulina platensis).The outcome of these medication is proved to have a hypoglycaemic effect and these can be used along with the dietotherapy in present scenario to reduce the risk of complications. This review paper will discuss the potential of hypoglycaemic effect of Gilo (Tinospora cordifolia) in Diabetes Mellitus.