Objective: The present study is aimed to evaluate an antidiabetic herbal tablet containing Oryza sativa L. var Joha Rice, Dillenia indica and Syzygium cumini Lam. of Assam. Material & Methods: The plants materials were obtained from local area and authenticated by botanist and extracted using solvent ethanol using soxlet apparatus. The poly herbal tablet is prepared using plant extracts with excipients by granulation method. The anti diabetic study of the herbal tablets were done in streptozotocin induced diabetic rats. Results: In our study we found that best two herbal tablet formulations in doses (250mg/kg, 500 mg/kg) significantly lowered the fasting blood glucose levels in rats compared to control group. Moreover, the effect continued to sustain after withdrawal of drug treatment. Similarly, these tablet formulations found to improve lipid profiles (TG, HDL, LDS, VLDL, TC) and serum creatinine level and body weight. Conclusion: It can be concluded that the prepared formulation of poly herbal antidiabetic tablets showed very good antidiabetic activity in animal studies. By further, clinical studies, we can prepare a cost effective herbal formulation for diabetes.