Tinospora crispa is a medicinal plant belonging to the botanical family Menispermiaceae. The plant is widely distributed in Southeast Asia and the northeastern region of India. A related species Tinospora cordifolia is used in Ayurveda for treating a large spectrum of diseases. Traditional healers of Thailand, Malaysia, Guyana, Bangladesh and the southern Indian province of Kerala use this plant in the treatment of diabetes. Many diterpenes, triterpenes, phytosteroids, alkaloids and their glycosides have been isolated from T. crispa. Cell culture and animal studies suggest that the herb stimulates secretion of insulin from β-cells. It also causes dose-dependent and time-dependent enhancement of glucose uptake in muscles. However, in view of the reported hepatotoxicity, this herb may be used with caution. This article reviews the animal studies and human clinical trials carried out using this herb. Areas of future research are also identified.