Plants are among the most prominent candidates in herbal medicine. Vast research is being performed for effective plants against diabetes. This experiment aimed to evaluate the effects of administering the methanolic extract of Neem (Azadirachta indica: MEN) at different concentrations, 150, 250 and 350 mg/kg body weight orally on the serum and body weight parameters of diabetic rats, and to compare these results with those of the standard medicated and non-diabetic control groups. The MEN and controls underwent a 28-day therapy, during which the impact on liver function parameters and serum glucose levels was observed. The estimated parameters included alanine aminotransferase, aspartate transferase, serum cholesterol, glucose, uric acid, urea, triglycerides, and creatinine. The results showed that the effects of the MEN were in a dose-dependent manner. There was a significant (p<0.05) increase in weight gain and a decrease in glucose levels in the treated groups. The lipid profile and liver and kidney function-related serum parameters remained normal in the groups treated with MEN at a dose rate of 350 mg/kg. The 350 mg/kg concentration results were comparable (p>0.05) to the standard medicated group. The findings of the study revealed that the administration of methanolic extract of Neem at a dose rate of 350 mg/kg can effectively control hepatic damage and serum parameters. Considering the findings from this research, it can be suggested that the methanolic extract of Neem seeds warrants further investigation as a potential antidiabetic agent. One important step in this process would be to identify the specific components of the extract that contribute to its effectiveness. Further research should be conducted to determine the optimal therapeutic dose of the methanolic extract of Neem seeds.