Heart failure is common and is associated with a poor prognosis. Chronic kidney disease is common in heart failure and shares many risk factors with heart failure, such as age, hypertension, diabetes, and coronary artery disease. Over half of all patients who have heart failure may have moderate-to-severe chronic kidney disease. The presence of chronic kidney disease is associated with increased morbidity and mortality, yet it is also associated with underuse of evidence-based heart failure therapy that may reduce morbidity and mortality. Understanding the epidemiology and outcomes of chronic kidney disease in heart failure is essential to ensure proper management of these patients.