It seems clear that beta blockers can limit infarct size in man and reduce mortality after a myocardial infarction. Early mortality also seems to be reduced by beta blockade in patients in whom infarct size was not limited. Thus, infarct size limitation is not the only mechanism for an effect of beta blockade on early infarction mortality. The favorable effect of early initiation of beta blockade on long-term survival might, however, suggest an importance of infarct size limitation for prognosis. More studies are needed to evaluate the role of infarct size limitation for long-term prognosis.