Risk stratification in unstable angina (UA)/non-ST-segment elevation myocardial infarction (NSTEMI) can provide an estimate of a patient's prognosis and optimize clinical choices. The Thrombolysis In Myocardial Infarction (TIMI) risk score for UA/NSTEMI is an integrated approach that uses baseline variables that are part of the routine medical evaluation to identify patients at high risk for death and other major cardiac ischemic events. Using multivariable logistic regression, seven independent predictor variables were identified: age > or = 65 years, > or = 3 risk factors for coronary artery disease (CAD), known CAD (stenosis > or = 50%), severe anginal symptoms (> or = 2 anginal events in preceding 24 h), use of aspirin in the last seven days, ST-segment deviation > or = 0.05 mV, and elevated serum cardiac markers of necrosis. Each predictor carried similar prognostic weight; therefore, a risk score was constructed as the simple arithmetic sum of the number of predictors. The rate of death, MI, or urgent revascularization significantly increased as the TIMI risk score increased, ranging from < 5% for patients with a risk score of 0 or 1 to > 40% for patients with a risk score of 6 or 7. The risk score has been validated in several other trials of UA/NSTEMI. In addition, using the risk score to categorize patients also effectively defines a gradient for benefit with specific treatments such as low-molecular-weight heparins, glycoprotein IIb/IIIa inhibitors, and an early invasive strategy.