Introduction. The purpose of this multicenter, prospective study was to assess differences in demographics, medical history, treatment times, and follow-up status among patients with ST-elevation myocardial infarction (STEMI), who were transported to the hospital by emergency medical services (EMS), privately, or transferred from other medical facilities.Methods. Our sample consisted of 455 patients admitted to 4 hospitals in “blinded for peer review.” We collected electronic medical records from EMS and hospitals, and conducted interviews with patients in-person or via telephone. Chi-square tests and Kruskal–Wallis tests were used to examine differences in variables by mode of transportation.Results. Results indicated significant differences in modes of transportation when considering symptom-onset-to-balloon-time (p < 0.001), door-to-balloon time (p < 0.001), and health status at 6-month and 1-year follow-up (p < 0.001). In all cases, EMS transportation was associated with a shorter time to treatment than other modes of transportation. However, the EMS group experienced greater rates of in-hospital events, including cardiac arrest and mortality, than the private transport group.Conclusion. Our results contribute data supporting EMS transportation for patients with acute coronary syndrome. Although a lack of follow-up data made it difficult to draw conclusions about long-term outcomes, our findings clearly indicate that EMS transportation can speed time to treatment, including time to balloon inflation, potentially reducing readmission and adverse events. We conclude that future efforts should focus on encouraging the use of EMS and improving transfer practices. Such efforts could improve outcomes for patients presenting with STEMI