Thrombolytic therapy for acute myocardial infarction is an important advance in patient care. The intravenous administration of tissue plasminogen activator appears to be the most promising combination of route and agent but may need to be coupled with more definitive measures. Although the prehospital use of thrombolysis is largely unexplored, the interhospital use appears to be safe and effective. The administration of thrombolytic therapy must be a coordinated effort between the emergency physician and the cardiologist. Indications for thrombolytic therapy are still evolving and adverse effects will no doubt increase in incidence once the availability and use of effective thrombolytic agents is widespread. The emergency physician, especially, needs to tread the fine line between "minutes are myocardium" and "haste makes waste."