Background: A coronary artery bypass graft is a complex procedure that can cause various physiological responses, including inflammation, oxidative stress, apoptosis, and endothelial dysfunction. Nevertheless, the correlation between these responses with organ function after CABG has not yet been established. This study aims to investigate the correlation between inflammation, oxidative stress, apoptosis, endothelial dysfunction markers, and postoperative organ function assessment as evaluated by the Cardiac Surgery Score (CASUS). Methods: A prospective cohort study was conducted on patients undergoing coronary artery bypass graft from two hospitals in Jakarta. IL-6, MDA, caspase-3, and syndecan-1 levels were measured at three points in time: before surgery, on ICU Day-1, and ICU Day-2. Postoperative organ function was assessed on ICU Day 2 by Cardiac Surgery Score (CASUS). Results: Fifty-one patients were included in the study. There was a positive correlation between IL-6 measured before surgery (r = 0.325, p = 0.020) and at the time of admission to the ICU (r = 0.374, p = 0.007). Positive correlation was also found between syndecan-1 levels on ICU day 1 (r = 0.304, p = 0.030) with CASUS. MDA correlated with CASUS on ICU day 2 (r = 0.392, p = 0.004); meanwhile, no significant association was found between caspase-3 and postoperative organ function assessment. Conclusion: Interleukin-6 levels pre-surgery and on ICU day 1, syndecan-1 levels on ICU day 1, and MDA levels on ICU day 2 were correlated with CASUS. © 2025, Indonesian Society of Internal Medicine. All rights reserved.