Cardiorenal syndrome (CRS) can be generally defined as a pathophysiologic disorder of the heart and kidneys whereby acute or chronic dysfunction of one organ may induce acute or chronic dysfunction of the other. A new classification of the CRS with 5 subtypes that reflect the pathophysiology, the time-frame, and the nature of concomitant cardiac and renal dysfunction has been presented. Interactions between inflammation, the renin-angiotensin system, the balance between the nitric oxide and reactive oxygen species and the sympathetic nervous system form the cardiorenal connectors and are cornerstones in the pathophysiology of CRS. Cardiorenal anemia syndrome refers to the simultaneous presence of anemia, heart failure (HF), and chronic kidney disease (CKD) that form a pathologic triangle with an adverse impact on morbidity and mortality. Interestingly, erythropoietin (Epo) can improve cardiac and renal function. There is evidence that the metabolic syndrome increases cardiovascular risk, independently from the concomitant effect of several traditional cardiovascular risk factors. Emerging data suggest that metabolic syndrome might also be a risk factor for chronic kidney disease, although its effects on the emergence of chronic kidney disease or its progression beyond the contribution of dysglycemia and high blood pressure are far from being established with certainty. Drugs that impair kidney function are undesirable, particularly in a population with already compromised or at-risk kidney function. In severe volume-loaded patients who are refractory to diuretics and also have kidney dysfunction, management of cardiorenal dysfunction is challenging, and effective therapy is lacking. New therapeutic avenues involving nesiritide, vasopressin antagonists, adenosine antagonists, endothelin antagonists and ultrafiltration are being investigated. In the absence of underlying primary renal parenchymal disease, mechanical ventricular assist devices or cardiac transplantation achieve reversal of the progressive cardiorenal syndrome. Finally, due to the absence of definitive clinical trials, treatment decision must be based on a combination of individual patient information and understanding of individual treatment options.