Chronic kidney disease (CKD) is one of the most powerful and independent predictors of adverse outcomes in patients undergoing cardiovascular surgery. As the global prevalence of CKD continues to rise, an increasing proportion of patients referred for coronary, valvular, or aortic surgery present with impaired renal function, creating a complex cardio-renal clinical scenario. CKD amplifies perioperative risk through multiple mechanisms, including chronic inflammation, endothelial dysfunction, vascular calcification, anemia, metabolic derangements, and reduced renal autoregulatory reserve. These factors substantially increase susceptibility to cardiopulmonary bypass–associated stress, ischemia–reperfusion injury, and postoperative acute kidney injury (AKI), which in turn accelerates long-term renal decline and mortality. Despite advances in surgical techniques and perioperative care, traditional cardiac risk models often underestimate risk in patients with moderate to advanced CKD, and the integration of nephrology-driven strategies into surgical pathways remains inconsistent. This chapter provides a comprehensive and up-to-date synthesis of the epidemiology, pathophysiology, risk stratification, and perioperative management of CKD in the setting of cardiovascular surgery. Emphasis is placed on multidisciplinary care, precision risk assessment, biomarker-guided surveillance, individualized perfusion and hemodynamic strategies, and structured postoperative and long-term follow-up. By integrating contemporary evidence, guideline recommendations, and emerging technologies, this work proposes a framework aimed at narrowing the persistent outcome gap between CKD and non-CKD patients undergoing cardiovascular surgery.