OBJECTIVES: We evaluated the independent impact of field triage on treatment delay and long-term clinical outcome in a large contemporary, consecutive population of ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (pPCI). BACKGROUND: Reduction of treatment delay is crucial for patients with STEMI. METHODS: From January 2005 to July 2008, 1,437 STEMI patients were treated with pPCI at a single high-volume invasive center. We present the 1-year outcome in this observational registry study. RESULTS: A total of 616 patients were admitted by field triage and 821 by emergency departments. Baseline and angiographic variables were similar in the 2 populations. Patients admitted by field triage had a significantly shorter median door-to-balloon time compared with patients admitted by emergency department triage (83 min, interquartile range 67 to 100 min vs. 103 min, interquartile range 80 to 135 min; p<0.001). Door-to-balloon times of less than the recommended 90 min were achieved in 61% of field triage patients, but only in 36% of nonfield-triage patients (p<0.001). After adjustment for relevant baseline variables, patients admitted by field triage had a reduced risk of reaching the combined end point of all-cause mortality or nonfatal myocardial infarction (hazard ratio: 0.67; 95% confidence interval: 0.46 to 0.97; p=0.035). CONCLUSIONS: This study shows that field triage of STEMI patients to pPCI significantly reduces treatment delay and improves outcome. These results emphasize the value of field triage as an important tool in the quest to improve clinical outcomes in STEMI patients undergoing pPCI.