The study evaluated rates and determinants of hospital morbidity, serious morbid events, and prolonged intensive care unit stay associated with isolated coronary artery bypass. The medical records of 391 patients undergoing isolated coronary artery bypass at our center during 2003 were reviewed. The observed crude hospital mortality rate was 2.05%, similar to the EuroSCORE predicted mortality rate of 2.34%. Arrhythmia was the most frequent postoperative complication (17.6%). The serious hospital morbidity rate was 5.9%. The final logistic regression model of serious morbid events identified the following predictors: drug allergy, diabetes, and EuroSCORE. Prolonged intensive care unit stay (>/= 3 days) was observed in 9.5% of patients. Multivariable logistic regression analysis revealed age, preoperative rhythm disturbances, previous cardiac operation, and hypertension as independent predictors of prolonged intensive care unit stay. The rates of hospital mortality, morbidity, and prolonged intensive care unit stay were comparable to those of other major international cardiac surgery centers. These data can be used as a benchmark for further self- and peer-assessment quality improvement activities.