Introduction: In this study, we aimed to compare the early postoperative period results of type 2 diabetes patients taking oral antidiabetics or insulin medications, with microalbuminuria and normal creatinine levels after coronary artery bypass. Materials and methods: Eighty patients with type 2 diabetes and taking oral antidiabetics or receiving insulin medication all with normal creatinine levels with microalbuminuria were included in this study. Preoperative creatinine values of the patients, albumin levels in spot urine, creatinine levels on the postoperative 3rd day, duration of ventilation, amount of drainage, length of stay in the intensive care unit, length of stay in the hospital, mediastinitis and mortality rates were recorded. Results: A statistically significant increase in creatinine was found in both taking oral antidiabetics type 2 diabetes and insulin medication patient groups with microalbuminuria. When the two groups were compared with each other, increase in creatinine levels of the patients using insulin was higher than the patients taking oral antidiabetics, and was statistically significant. Conclusion: According to the result of our study it can be suggested that postoperative creatinine elevation is observed in patients with type 2 diabetes mellitus with microalbuminuria and with normal creatinine levels, either having insulin medication or not. The elevation is higher in patients having insulin medication while other results are similar, except for impaired renal function. Keywords: Type 2 diabetes mellitus, insulin, microalbuminuria, coronary artery bypass.