The coronary blood flow and heart contractile function were studied on rats with phenylhydrazine-induced chronic hemolytic anemia. The coronary blood flow in the animals' hearts was increased 2.5-fold, whereas the main parameters of contractile function were reduced but insignificantly. After the coronary blood flow dropped to the control level, the pressure and contraction rate fell by 40% and the relaxation rate diminished 2-fold. Thus, the enhanced coronary blood flow in the hearts of animals with hemolytic anemia appears to be a factor that compensates for the maintenance of myocardial contractility at the subnormal level. Administration of the antioxidant ionol, an inhibitor of lipid peroxidation, coupled with phenylhydrazine did not prevent the development of anemia but made the coronary blood flow descend in the hearts of anemic animal only by 80%. Since the iron-containing products of red cell dissolution activate lipid peroxidation during hemolytic anemia, this might play a role in the occurrence of heart muscle injuries. It is suggested that ionol prevents such injuries to a considerable extent, thereby preventing the development of compensatory enhancement of the coronary blood flow and heart contractile function disturbances during its normalization.