BACKGROUND: Time from symptom onset to reperfusion is essential in patients with ST-segment elevation acute myocardial infarction. Prior studies have indicated that prehospital 12-lead electrocardiogram (ECG) transmission can reduce time to reperfusion. PURPOSE: Determine 12-lead ECG transmission success rates, and time saved by referring patients directly to primary percutaneous coronary intervention (pPCI) bypassing local hospitals and emergency departments. METHODS: Prehospital 12-lead ECG was recorded in patients with symptoms suggesting acute coronary syndrome during a 1-year pilot phase and transmitted to the attending cardiologist's mobile phone. Transmission success rates were determined, and prehospital and hospital delays were recorded and compared to historic controls. RESULTS: Transmission was attempted in 152 patients and was successful in 89%. Twenty-seven patients were referred directly for pPCI. Median hospital arrival to pPCI was 22 vs 94 minutes in the control group (P < .01). CONCLUSIONS: Transmission of prehospital ECG is technically feasible and reduces time to pPCI in ST-segment elevation acute myocardial infarction patients.