Type 5 cardiorenal syndrome (CRS) is a recently defined clinical syndrome for which complete epidemiological data is still missing. Type 5 CRS occurs when heart and kidneys are involved at once. The pathophysiology of type 5 CRS depends on the underlying disease. Acute type 5 CRS results from systemic processes, e.g. sepsis, infections, drugs, toxins, and connective tissue disorders such as lupus, Wegener's granulomatosis, and sarcoidosis. By contrast, the chronic type 5 CRS (i.e. cirrhotic liver disease) has a more insidious onset, as the kidney and cardiac dysfunction may develop slowly until reaching a crucial point leading to full decompensation. Diagnosis is based both on serological (biomarkers of acute cardiorenal disease, creatinine, and GFR levels) and imaging methods (echocardiography and abdominal ultrasound). Therapy is based on management of the underlying disease and treatment of cardiorenal complications (fluid therapy, drugs, and renal replacement therapy devices).