Background: Patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) are at particularly high risk of contrast-induced nephropathy (CIN), which, when occurring, may be followed by persistent worsening of renal function. The aim of this work was to validate CHA2DS2-VASc score as a novel predictor for contrast-induced nephropathy, irrespective to atrial fibrillation, after percutaneous coronary intervention in acute coronary syndrome. Methods: This was a single center, prospective cohort, non-randomized, observational study. This study included 200 patients with acute coronary syndrome who were planned for percutaneous intervention referred to the Department of Cardiology, Universal medical insurance tertiary hospital, Port Said, in the period between September, 2021 to January 2022. These patients were divided into two groups as: Group 1 (with CIN) and Group 2 (without CIN). Results: The current study showed that, CIN cases were significantly associated with higher CHA2DS2-VASc score when compared to those with no CIN. The optimal cut off value was 4, sensitivity was 75%, specificity was 71.4%, PPV was 33.3%, NPV was 93.7%, and accuracy was 72%. For the presence of CHA2DS2-VASc score