In the era of multiple new therapies (e.g., aspirin, beta blockers, thrombolysis, angiotensin-converting enzyme inhibitors, etc.) with the potential to improve outcome, the utility of traditional methods for predicting risk for adverse outcome after acute myocardial infarction (MI) is being reevaluated. Recent data suggest that heart failure, male gender, older age, and ischemia on ambulatory electrocardiogram (ECG) monitoring are the best predictors for increased risk of death or nonfatal MI. Exercise stress testing and ejection fraction determination provide little, if any, additional prognostic information. A new, highly promising strategy is to assess the degree of resolution in ST-segment elevation on repeated ECG monitoring following thrombolytic therapy. Studies have shown that failure to achieve prespecified degrees of ST-segment resolution within the first few hours of thrombolytic therapy is a reliable indicator of risk for post-MI mortality. Emerging data are also raising the possibility that cardiac troponin-T levels can be utilized as an important prognostic marker for adverse outcome in patients who present with acute ischemic syndromes.