© 2021 Medisinsk Fysiologisk Forenings Forlag (MFFF).Background: This study aimed to evaluate thiol disulphide volume for the risk of contrast-induced nephropathy (CIN) in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). Methods: A total of 638 patients with ACS were enrolled in the study. CIN was defined as an increase in serum creatinine level of ≥0.5 mg/dL or ≥25% above baseline within 72 h after the procedure. Patients were divided into two groups: patients with and without CIN. Demographics, clinical risk factors, angiographic and laboratory parameters, CIN incidence, thiol, disulphide, and CHA2DS2-VASc score were compared between the two groups. Results: Native thiol, total thiol, and disulphide at baseline were significantly lower in patients who developed CIN compared to those who did not. Also, the CHA2DS2-VASc score was found to be higher in patients with CIN than those without CIN. In receiver operating characteristic analysis showed that at a cutoff of <342.1, the value of native thiol exhibited 82% sensitivity and 80% specificity for detecting CIN. Total thiol< 383.1 calculated on admission had an 80% sensitivity and 80% specificity in predicting CIN. Conclusion: Our study suggested that the thiol disulphide volume on admission was independently associated with the development of CIN after PCI in patients with ACS.