Thisstudy examines the potential number of patients who would be diverted from hospitals without percutaneous coronary intervention (PCI) capability, to centers with this capability, as a result of prehospital triage strategies for patients with suspected acute myocardial infarction (AMI). All patients with AMI admitted during a 1-year study period at two urban hospitals without PCI capability were identified through a prospectively maintained AMI registry. Pertinent clinical data were extracted from the AMI registry and patients' medical records. Patients were considered to have been eligible for prehospital diversion to a PCI center if they had ischemic symptoms of greater than 20 min and less than 24 h duration, and electrocardiographic changes consistent with ST elevation AMI (STEMI) were noted at the time of Emergency Department (ED) arrival or before arrival. There were 176 patients with AMI identified. One hundred three patients were transported to the ED by Emergency Medical Services (EMS). Of these, 39 had a clinical presentation and diagnostic EKG evidence of STEMI on ED arrival. Implementation of a prehospital triage strategy for patients with suspected STEMI may result in the diversion of 22% of patients with AMI from hospitals without PCI capability, assuming perfect specificity of prehospital triage. Actual implementation of a prehospital AMI diversion protocol may have an even greater impact on nonreceiving hospitals.