The heart supplies oxygen-rich blood to tissues and organs, and the kidneys need to be well perfused by the heart in order to function properly in their role of maintaining fluid and salt homeostasis; therefore, it is not surprising that there is an intricate relationship between these two organs. Many studies have examined the pathophysiology and treatment options for renal failure and heart failure as separate entities, but fewer studies have investigated them jointly. Furthermore, between the many subtypes of cardiorenal syndrome, the ambiguity of contrast-induced versus cardiac-induced nephropathy after invasive cardiac procedures, and the prevalence of concomitant cardiac and renal disease, there is a need for a broad collective review of cardiac and renal disease. This article examines the pathophysiology behind cardiorenal syndrome, contrast-induced nephropathy after invasive cardiac procedures, and acute kidney injury after cardiac surgery, together with the data supporting currently available prevention and treatment options.