The goal of this study was to assess the relationship of postoperative atrial fibrillation (AF) with the use of blood products and postoperative hemoglobin levels following coronary artery bypass grafting (CABG). Eighty patients undergoing isolated CABG from June 2013 to December 2013 in our institution were included in this study, and divided into two groups that contain 40 patients according to their postoperative blood hemoglobin levels in this prospective study. In Group 1 and 2, there were patients that whose postoperative hemoglobin levels were below 10 g/dL and above 10 g/dL, respectively. Groups were compared with each other according to the use of blood products and occurrence of AF, then the relationship between use of blood products and occurrence of AF was analyzed. Moreover, patients that occur postoperative AF and patients that do not occur postoperative AF were compared with each other; thus, risk factor analysis for postoperative AF were performed. Postoperative AF was observed in 12 (30%) patients in Group 1 (mean age: 62.0±9.6 years, 24 male) and 7 (17.5%) in Group 2 (mean age: 60.3±9.0 years, 27 male), but this difference was not found to be statistically significant. When patients that occurred AF and did not occur AF were compared, according to the number of patients that had received blood products, the patients that had occurred AF had received more blood products than the patients whom had not occurred AF although again this difference was not statistically significant. In risk factor analysis; advanced age, low ejection fraction, obesity and the non-use of preoperative beta blocker were found to be risk factors associated with postoperative AF. In accordance with this study, the use of blood products and postoperative hemoglobin levels do not have an important impact on AF that occurs in patients undergoing isolated CABG. However, further studies with larger patient series are needed to elucidate this relationship.