The objective of this study was to determine the safety of the glycoprotein Ilb/IIa receptor inhibitor eptifibatide in patients at high risk for adverse clinical outcomes and to determine risk factors for eptifibatide-associated bleeding. Consecutive patients (n =175) who presented with an acute coronary syndrome and who were at high risk for adverse clinical outcomes were prospectively observed for eptifibatide-associated bleeding, which was classified according to Thrombolysis in Myocardial Infarction (TIMI) and Global Use of Strategies to Open Occluded arteries (GUSTO) criteria. High risk was defined as unstable angina or non-Q-wave myocardial infarction with at least one of the following: left ventricular ejection fraction < 40%, diabetes mellitus, ST segment depression or transient ST segment elevation, serum [troponin I] > 2.5 ng/mL, and recurrent angina symptoms after initiation of conventional antianginal therapy Bleeding incidences in thepatients in this study were compared with those in the 4722 eptifibatide-treated patients in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial. Compared to PURSUIT patients, the population in this study was similar in age but had a higher proportion of females, African Americans, hypertension, diabetes, prior myocardial infarction, heart failure, and revascularization. Bleeding incidences in this study's patients were similar to or lower than those in the PURSUIT population: TIMI major 1.1% versus 10.8%, TIMI minor 12.6% versus 13.1%, GUSTO severe 1.7% versus 1.5%, GUSTO moderate 3.9% versus 11.3%, and GUSTO mild 19.7% versus 26.1%. Renal dysfunction was an independent risk factor for TIMI (odds ratio = 9.1 [95% CI= 1.6–52.5]) and GUSTO (odds ratio = 6.1 [95% CI = 1.2–30.0]) bleeding. In conclusion, despite being at higher risk for adverse outcomes, patients administered eptifibatide according to this study's institutional guidelines had comparable or lower bleeding rates than in the PURSUIT trial. Renal dysfunction is an independent risk factor for eptifibatide-induced bleeding.