Data are sparse regarding long-term outcomes after hospitalization for unstable angina pectoris (UAP) and non-ST-elevation myocardial infarction (NSTEMI), as defined by contemporary criteria. We extended follow-up in a preexisting database of unselected patients with primary UAP and NSTEMI admitted by way of the emergency department from 1991 to 1992. Stepwise Cox models were used to identify multivariate predictors of long-term mortality. There were 275 patients (mean age 66 +/- 12 years, 33% women) who survived to hospital discharge; 134 patients (49%) died during follow-up (median 9.4 years). Significant multivariate predictors of long-term mortality were: age (hazard ratio [HR] per decade 1.7, 95% confidence interval [CI] 1.4 to 1.9); prior MI (HR 1.7, 95% CI 1.2 to 2.5); diabetes (HR 1.7, 95% CI 1.2 to 2.4); congestive heart failure (HR 2.2, 95% CI 1.5 to 3.4); elevated creatinine (HR 2.5, 95% CI 1.7 to 3.8); elevated leukocyte count (HR 1.7, 95% CI 1.1 to 2.5); systolic blood pressure <120 mm Hg at presentation (HR 2.0, 95% CI 1.1 to 3.6); lack of coronary revascularization during the index hospitalization (HR 2.0, 95% CI 1.3 to 3.0); and lack of discharge beta-blocker therapy (HR 1.5, 95% CI 1.1 to 2.2). A clinical prediction rule was generated by assigning weighted point scores for the presence of each significant covariate. Long-term mortality increased markedly with each quintile of score; for quintiles 1 to 5, mortality rates were 8.5%, 29.4%, 47.6%, 75.0%, and 91.5%, respectively (p value for trend <0.001). These data are among the first assessments of long-term mortality after hospitalization for primary UAP and NSTEMI, as defined by contemporary guideline criteria. Easily obtained clinical covariates provide excellent prediction of long-term mortality up to 10 years after hospitalization for primary UAP and NSTEMI.