Background: Diabetes Mellitus is a syndrome characterised by a loss of glucose homeostasis from defective insulin secretion and its action; both are resulting in impaired metabolism of carbohydrate, lipid and protein. Diabetes mellitus, if uncontrolled, leads to many complications and the significant being atherosclerosis. Diabetes Mellitus could be treated by nutritional therapy/drug therapy and others. But the drug therapy would have its limitations and side effects. To overcome this, a herbal extract is recommended, such as Diallyl Disulphide (DADS) a principle compound of Garlic oil. Objectives: To assess the hypoglycaemic and hypolipidemic effects of Diallyl Disulphide (DADS) in alloxan-induced diabetic rats. Methods: Healthy adult Wister strain male albino rats, weighing around 100-150 grams were randomly selected from the animal house at BLDE University’s Shri B.M.Patil Medical College, Hospital and Research Centre, Bijapur, India. Diabetes was induced using alloxan and was treated with DADS. After a stipulated time, the rats were anaesthetised and sacrificed to collect the blood. Blood glucose and serum lipid profile were estimated using standard procedures. One way ANOVA followed by post hoc‘t’ test was done. Results: There was a significant decrease in the blood glucose, and lipid parameters of DADS treated alloxan-induced diabetic rats when compared to the alloxan-induced diabetic rats. Conclusion: From this study, it is concluded that the DADS a principle compound of garlic, definitely has the hypoglycaemic and hypolipidemic effect in diabetic rats, which is reducing the morbidity in diabetic cases without the adverse effects.