Objectives: Diabetes mellitus is a group of chronic diseases in which the body has problems with the use or production of glucose, the main source of energy for metabolism. This condition can affect the metabolism of carbohydrates, fats, and proteins, potentially leading to chronic hyperglycemia (high blood sugar levels). The present study investigated the effects of soybean (Glycine max L.) seed extract on various biochemical parameters and pancreas weight in Wistar rats with experimental diabetes. Methods: The study consisted of five groups of rats: control, diabetic, and treated (100, 200, and 400 mg/kg extract). To induce diabetes in rats, Streptozotocin (STZ) was administered through intraperitoneal injection (35 mg/kg). The rats were orally given water-soluble extracts at the indicated quantities once daily for four weeks. Venous blood was collected from the animals via heart puncture, after which the animals were sacrificed. Biochemical parameters, including blood glucose, were measured using an autoanalyzer. Results: In diabetic rats, there was a significant increase in serum glucose concentration (p<0.05). However, treatment with soybean resulted in a significant reduction (p<0.05) of the elevated glucose concentration in the treated diabetic rats. It is noteworthy that the glucose concentrations were still significantly higher (p<0.05) than those of the control group. Biochemical parameters, including urea, AST, SGPT/ALT, cholesterol, triglycerides, glucose, LDL-cholesterol, and VLDL-cholesterol, were lower in the treated groups than in the diabetic control group and were considered significant (p<0.05). Moreover, it was observed that the HDL-cholesterol parameter was significantly higher than that of the diabetic control group (p<0.05), while the creatinine parameter was not found to be statistically significant (p>0.05). Conclusion: The results suggest that soybean treatment may have a positive impact on certain biochemical parameters in diabetic rats. These findings are consistent with previous reports on the health benefits of soybean. It can be inferred that G. max may have a hypoglycemic effect in diabetic rats and could potentially mitigate the complications of diabetes mellitus.