Obesity is a global problem since not health risk but also cosmetic value is attached to it. Many genetic, environmental, behavioral, and cultural factors affect health. Diet is as vital as any of them for preventing disease and promoting well-being. The solution to this problem may lie in our traditional medicine where Horse gram grain (Dolichos biflorus), in the form of decoction is indicated in corpulence (obesity). So this study was planned to find out anti-obesity activity of Dolichos Biflorus (Horse gram), compared to 5HT in Albino Rats. After obtaining animal ethics committee approval this study was carried out. Albino rats were divided to four groups (three males and three female in each group). Hot and cold extract of horse gram seed was prepared. Then anti obesity activity was compared with groups treated with 5HT and control group. It was found that Horse gram has antiobesity activity comparable with 5HT. Unlike 5HT, this response of Horse gram was influenced by gender. Magnitude was more pronounced in male than in female. Hot extract brings about weight reduction in male but only retardation of weight gain in female. Tolerance develops on chronic use in all groups.