Background: Coronary artery disease (CAD) and chronic kidney disease (CKD) may reciprocally influence each other. Patients with CAD and CKD have an increased risk of both ischemic and hemorrhagic events. Methods: In the present review, we summarize the existing literature focusing on the relationship between kidney dysfunction and acute coronary syndromes (ACS) in terms of risk factors, complications, and prognosis. We discuss also about the best evidence-based strategies to prevent deterioration of renal function in patients with CAD. Results: Patients with CKD less frequently receive an invasive management (percutaneous or surgical revascularization) and potent antithrombotic drugs. Nevertheless, recent evidence suggests they would benefit from a selective invasive management, especially in case of ACS. Conclusion: Patients with CKD and CAD represent a challenging population, more randomized controlled trials and meta-analyses are needed to better define the best therapeutic strategy during an ACS episode.