Introduction: Coronary artery bypass grafting is a safe procedure performed worldwide with low rates of mortality and morbidity in general population. Objective: To investigate risk factors for mortality of patients undergoing coronary artery bypass grafting coronary artery bypass grafting surgery. Methods: A total of 1,628 consecutive patients undergoing on-pump coronary artery bypass grafting were retrospectively studied from December 1999 to February 2012. Data analysis involved paired Student t test, Mann-Whitney test and Fisher's exact test for the categorical data. Logistic regression, Odds Ratio and 95%CI were used for definition of risk factors for mortality. Results: Of a total of 1,628 patients undergoing on-pump coronary artery bypass grafting, 141 (8.7%) died. The following risk factors for mortality were identified after logistic regression: dialysis (OR=7.61; 95% CI 3.58-16.20), neurologic dysfunction type I (OR=4.42; 95% CI 2.48-7.81), use of IABP (OR=3.38; 95% CI 1.98-5.79), cardiopulmonary bypass time (OR=3.09; 95% CI 2.04-4.68), serum creatinine on admission and peak values >0.4mg/dL (OR=2.67; 95% CI 1.79-4.00), age >65 years (OR=2.31; 95% CI 1.55-3.44), and time between hospital admission and and surgical procedure (OR=1.53; 95% CI 1.03-2.27). Conclusion: Dialysis, type I neurologic dysfunction, use of IABP, cardiopulmonary bypass time (>115 minutes), serum creatinine on admission and peak values >0.4mg/dL, age >65 years and time between hospital admission and surgical procedure were considered as risk factors for mortality in patients undergoing on-pump coronary artery bypass grafting surgery.