In patients with acute myocardial infarction, early reperfusion and sustained patency of the culprit artery are important determinants of survival. The 12-lead electrocardiogram (ECG) is considered the noninvasive gold standard for identification of acute ST-elevation myocardial infarction. Nurses play a critical role in the process of obtaining, interpreting, and communicating ECG findings. This study evaluates nurses' ability to differentiate ischemic from nonischemic ECG patterns, to detect affected ECG leads and location of ischemia, and assesses skill level by hospital unit type. Seventy-five nurses were given a set of 6 patient scenarios, each with a corresponding 12-lead ECG, and asked to identify the presence or absence of ischemia. Fourteen (19%) of the 75 nurses correctly identified the presence or absence of ischemia in all 6 scenarios. Of the 3 ECGs with a myocardial infarction pattern, 59 (79%) of the nurses identified all 3 as ischemic; however, no one was able to determine the correct leads, location, or amplitude of ST-segment elevation. For the 3 nonischemic ECGs, 37 (49%) of the nurses identified a normal ECG as ischemic, 47 (63%) determined that an early repolarization pattern was ischemic, and 34 (45%) indicated that a left bundle branch block pattern was ischemic. These results not only identify educational opportunities but also provide important information for researchers implementing clinical trials evaluating the use of bedside ECG monitoring systems for detection of acute myocardial ischemia.