Background: Although guidelines strongly recommend use of the Emergency Medical Systems (EMS) by patients with acute myocardial infarction (AMI), it remains underutilized in western countries. Information about its current use in China is unclear. The objective of this study was to examine the use of the EMS by patients with AMI in China, and investigate factors affecting its use. Methods: A prospective survey study, which included 803 patients with AMI who were admitted to 21 hospitals in China between November 1, 2005 and December 31, 2006. Results: Only 39.5% of patients called up the EMS at the onset of symptoms (EMS group, n = 317), whereas the rest presented to the hospital by some other means (self-transport group, n = 486, 60.5%). Predictors of EMS users were older age, symptom onset at evening, unbearable symptoms, having received training and acquired knowledge on heart attack, as welt as having a higher income and medical history of heart failure or stroke. Prehospital delay (median 110 min vs. 143 min, p < 0.001), door to needle time (median 85 min vs. 93 min, p < 0.005) and door-to-balloon time (median 118 min vs. 160 min, p < 0.001) were significantly shorter in the EMS group. The early reperfusion rate was also significantly higher in the EMS group (84.8% vs. 78.2%, p = 0.019), mainly because of a greater incidence of primary percutaneous coronary intervention (68.1% vs. 61.7%, P = 0.046). Conclusions: The emergency medical services are underutilized by patients with AMI in China. Use of the EMS may be advantageous in view of greater administration of reperfusion therapy. New public health strategies should be developed to facilitate greater use of the EMS for AMI.