Emergency medical services (EMS) providers who administer advanced life support should include diagnostic 12-lead electrocardiography programs as one of their services. Evidence demonstrates that this technology can be readily used by EMS providers to identify patients with ST-segment elevation myocardial infarction (STEMI) before a patient's arrival at a hospital emergency department. Earlier identification of STEMI patients leads to faster artery-opening treatment with fibrinolytic agents, either in the pre-hospital setting or at the hospital. Alternatively, a reperfusion strategy using percutaneous coronary intervention can be facilitated by use of pre-hospital 12-lead electrocardiography (P12ECG). Analysis of the cost of providing this service to the community must include consideration of the demonstrated benefits of more rapid treatment of patients with STEMI and the resulting time savings advantage shown to accompany the use of P12ECG programs.