Background: Diabetes causes increased oxidative stress, to play an important role in the pathogenesis of various diabetic complications. The present study investigated the protective potential of allicin against diabetes in rat model. Methodology: Animals were injected a single dose of streptozotocin (55mg/kg.b.wt) to induce diabetes. Control and diabetic rats were treated with allicin (20 mg/kg.b.wt) for 30 days.  Glibenclamide (10mg/kg.b.wt) was used as a positive control. After the experimental regimen, the rats were sacrificed and the blood was collected and serum was separated. Blood sugar, body weight, total protein, oxidative stress markers (TBARS, CAT, SOD and GSH) and inflammatory markers (TNF-α and IL-6) were used to bio-monitor the protective potential of allicin. Results: The experimental animals lost weight significantly, exhibited elevated blood sugar levels, decreased protein levels (p<0.05) in comparison to control animals; these alteration were corrected after allicin therapy. The significant elevation of TBARS content, reduction in total glutathione content and declined CAT and SOD activities in experimental animals; which were normalized following allicin therapy. The altered serum inflammatory markers were significantly reduced to near normal levels. No significant alterations in allicin alone administered rats. Conclusion: We thus conclude that allicin has potent antihyperglycemic, anti-lipidperoxidative and anti- inflammatory potential in diabetic animals.