Myocardial reperfusion is today the best alternative to save ischemic myocardium. However, reperfusion carries with him an aggressive potential that may mask its benefits. From a clinical point of view, it is necessary to create new complementary therapies to prevent such injury. One of such therapy in which a great deal of knowledge in experimental models has been accumulated is superoxide dismutase. In this work are presented some chemical, biological, and pharmacological characteristics of this enzyme. Several forms of reperfusion injury are discussed as well as the role of superoxide dismutase in their prevention. The experience gathered along the years is still small for prevention of cellular oedema, intramyocardial haemorrhage, and low/no-reflow. There is still some controversy about the role of superoxide dismutase in the reduction of myocardial necrosis. However, superoxide dismutase seems to be highly protective, as far as stunned myocardium and reperfusion arrhythmias are concerned.