This study evaluated the biochemical and the hematological parameters in diabetic and non-diabetic patients. The measured biochemical parameters were fasting blood sugar, serum alanine aminotransferase (SGPT/ALT), total cholesterol, urea, creatinine and hematological parameters were hemoglobin, total white blood cell, neutrophil, lymphocyte, monocyte, eosinophil and ESR. There were 403 diabetic and 320 non-diabetic subjects included in this study and the study was carried out in BIRDEM (Bangladesh Institute of Research & Rehabilitation in Diabetes, Endocrine and Metabolic Disorders) General Hospital). It was observed that the mean values of SGPT/ALT (p< 0.001), total cholesterol (p< 0.001) and creatinine (p< 0.001) of biochemical parameters, and Monocyte (p< 0.001), Eosinophil (p< 0.004), ESR (p< 0.001) of hematological parameters were significantly higher in diabetic patients than in the nondiabetic patients. In univariate analysis, all biochemical parameters and only four hematological parameters were found significantly associated with fasting blood sugar after adjusted with age and sex. The fasting blood sugar correlates highly with the other biochemical parameters but less or none with the hematological parameters. Our findings demonstrated that control of increased biochemical parameters and abnormal hematological levels in the early stage of diabetes mellitus may help the patients to raise quality of life.