BACKGROUND:The incidence rate of diabetes mellitus has increased throughout the year. Various studies indicate that smoking may affect glucose metabolism and cause hyperglycemia in diabetes mellitus. This study aimed to compare the blood glucose and HbA1c level in diabetic smoking patients and non-smoking diabetic patients.METHODS:This study used the cross-sectional approach. The study population consisted of 30 diabetic smoking patients and 30 non-smoking diabetic patients. The diabetes history and the smoking status of the study population obtained by questionnaire-based interview, the blood glucose and HbA1c level were measured by hexokinase and immunoturbidimetry method using cobas 6000 analyser module c501 (Roche Diagnostics, Switzerland).RESULTS:The result in this study showed the fasting blood glucose, postprandial blood glucose, and HbA1c were higher by 23.64 mg/dl (p = 0.325), 58.00 mg/dl (p = 0.016), 0.39% (p = 0.412) in smoking diabetic patients compared to non-smoking diabetic patients. After statistical analysis, there was a significant difference (p < 0.05) of postprandial glucose level between smokers group and non-smokers group, but the non-significant difference of fasting blood glucose and HbA1cCONCLUSIONS:This study concluded that there was a significant difference in postprandial glucose level between smokers group and non-smokers group but the non-significant difference of fasting blood glucose and HbA1c.