Nowhere in emergency medicine are mythology, legend, and tradition as conspicuous as they are in the field of prehospital care (EMS). Images of speeding ambulances with lights and sirens, aeromedical helicopters in flight, and heroic medical interventions in austere environments are awe-inspiring, thrilling, and reassuring to many of us. As dispassionate scientific scrutiny is applied to these and other practices in EMS, however, it becomes evident that many of the current practices and protocols in EMS are not based on any level of scientific evidence. This article will review current evidence about the costs and benefits of some of the most common current practices in EMS. These include the use of lights and sirens and helicopters, endotracheal intubation and its alternatives in airway management, cardiopulmonary resuscitation, advanced cardiac life support, public access defibrillation, and analgesics. It is hoped that by shining the light of scientific scrutiny upon these practices, dogma will be replaced by clinical evidence. Only in this way may cost-effective emergency care be provided for the greatest benefit to the largest number of citizens.