OBJECTIVE: Analysis of heart rate variability (HRV) is a non-invasive method for assessing cardiac autonomic regulation. This study was designed to investigate whether preoperative short-term HRV analysis could identify the patients at high risk of atrial fibrillation (AF) after coronary artery bypass grafting (CABG). DESIGN: HRV measurement was performed preoperatively for 92 elective CABG patients. RESULTS: Thirty patients had AF postoperatively while 62 remained in sinus rhythm (SR). Logistic regression analysis identified two independent predictors for AF after CABG: increased age with an odds ratio (OR) 1.06 per year and higher body mass index (BMI) with an OR 1.18 per unit. However, no measured parameters of HRV analysis differed significantly between AF and SR groups. CONCLUSION: The patients at high risk of AF after CABG cannot be identified by preoperative short-term HRV analysis performed during standardized physiological conditions. Advanced age and higher BMI were independent risk factors of AF after CABG in this study.