Objective: Atrial fibrillation (AF) remains the most commonly observed complication following myocardial revascularization surgery. We aimed to evaluate the clinical utility of NT-pro-BNP, troponin T, transcoronary lactate gradient (TCLG) and C-reactive protein as predictors of atrial fibrillation in patients undergoing isolated CABG. ----- Methods: Two hundred and fifteen consecutive patients in sinus rhythm (SR) undergoing elective CABG between May 2007 and May 2008 were included. Patients were grouped according to their respective postoperative rhythm into SR and AF groups. The data are presented as mean values ± standard deviation, or medians with quartiles. ----- Results: Fifty five patients developed AF (26%). The preoperative NT-pro-BNP values were 273 ± 347 and 469 ± 629 pg/ml in the SR and AF groups, respectively (p < 0.0001). The postoperative NT-pro-BNP values were 3110 ± 3600 in the SR and 4625 ± 5640 pg/ml in the AF group (p = 0.027). The transcoronary lactate gradient rose from the pre-cardiopulmonary bypass (CPB) values to those observed 5 minutes after revascularization in both groups (-0.05 ± 0.37 to 0.39 ± 0.46 mmol/l (p < 0.0001) in the SR group and -0.01 ± 0.27 to 0.43 ± 0.46 mmol/l (p < 0.0001) in the AF group). The CRP values increased from 6 ± 13 to 163 ± 88 mg/L (p < 0.0001) in the SR group, and from 6 ± 16 to 163 ± 104 mg/l (p < 0.0001) in the AF group. The dynamics of TCLG and CRP did not differ between the groups (p = 0.71, p = 0.44, respectively). The troponin T values on postoperative day one were significantly higher in the AF than the SR group (0.86 [0.49-2.1] ng/ml vs. 0.67 [0.37-1.16] ng/ml, p = 0.046). The duration of cardiopulmonary bypass (CPB) was 85 ± 24 in the SR and 93 ± 30 min in the AF group (p = 0.05). Patients who developed AF were older (66 ± 7 vs 60 ± 9 years, p < 0.0001) and had a higher EuroSCORE (3.9 ± 2.7 vs 2.9 ± 2.2, p = 0.009). Multivariate analysis identified age (p = 0.0043), preoperative NT-pro-BNP (p = 0.019) and duration of cardiopulmonary bypass (p = 0.035) as independent predictors of AF. ----- Conclusions: Preoperative and postoperative NT-pro-BNP, as well as, TnT values were significantly higher in patients that subsequently developed AF. TCLG and CRP were not useful in identifying patients at higher risk for AF. Multivariate analysis identified age, preoperative NT-pro-BNP and duration of CPB as independent correlates of AF.