Atypical hemolytic uremic syndrome (aHUS) is a rare and heterogenous disease caused by a disregulation of the alternative pathway of the complement cascade. Specifically, microvascular damage is produced that can lead to acute kidney disease, hemolytic anemia and thrombocytopenia. It accounts for 10% of all hemolytic uremic syndromes and can result in death or in end stage renal disease since the first episode. We can differentiate two forms of aHUS: a sporadic form (80%), affecting adult people, and a familial form (20%) that usually became manifest during infancy. In the acute phase of the disease, frequent and severe anemia requires multiple blood transfusions, exposing patients to the risk of catching an infective disease. HCV hepatitis is the most prevalent chronic hepatitis worldwide, with approximately 170 million chronically infected individuals – many of which are unaware of their condition. The evolution of the HCV infection is variable: almost 20% of patients spontaneously clear the infection over time (Anti HCV positive, HCV RNA negative patients); 80% of patients cannot control the virus and develop chronic infection (Anti HCV positive; HCV RNA positive patients) that can evolve into liver cirrhosis and hepatocellular carcinoma. The aim of this paper is to describe a clinical case of acute HCV hepatitis in a patient with aHUS treated with Eculizumab.Copyright by Società Italiana di Nefrologia SIN, Rome, Italy.