Hemolysis is a frequent complication of the implant of prosthetic valves, and is conditioned by a variety of factors, most of which related to the type of valve implanted and to the hemodynamic conditions following implantation. If sufficiently severe, it may lead to varying degrees of hemolytic anemia. The following laboratory tests are useful to diagnose and assess the severity of hemolytic anemia: hemoglobin levels; reticulocyte count; the demonstration of schistocytes on a blood smear; serum levels of lactic dehydrogenase, haptoglobin and iron. Treatment of hemolysis includes the supplementation of iron and folate when their deficiency is evident. Transfusions are necessary only in cases of severe anemia refractory to treatment. The use of beta-blockers appears to decrease the severity of hemolysis, likely because of the induction of bradycardia and of their negative inotropic effects. Some cases have been described of erythropoietin treatment for hemolytic anemia in these conditions, with favorable outcome. However erythropoietin use should currently be restricted to patients with severe hemolytic anemia in whom surgical repair or transfusions should be avoided or deferred. The recognition and the estimation of severity of hemolysis after valve implantation are important steps in the patients' follow-up and the premise for a rational treatment.