Abstract: AIM: To evaluate the risk factors of bleeding complication of tirofiban in elderly patients with acute coronary syndrome (ACS). METHODS: A total of 67 patients (>60 years) with ACS were enrolled from August 2008 to February 2009 and were all given aspirin, clopidogrel, low molecular weight heparin, tirofiban and other anti-ischemic therapy. Tirofiban was given continuously for 36-48 h. Possible risk factors of bleeding complication analyzed included age, sex, smoking, hypertension, diabetes mellitus, blood platelet number, platelet aggregation, body mass index and creatinine clearance rate. RESULTS: Of the six bleeding patients, one patient experienced severe bleeding and five experienced mild bleeding. The results of multivariate stepwise logistic regression analysis indicated that smoking (OR=3.2, 95% CI 2.2-4.6), age (increasing every 10 years, OR=1.4, 95% CI 1.1-1.7), platelet aggregation (decreasing 10% OR=1.6, 95% CI 1.2-1.9), creatinine clearance (decreasing 10 ml/min OR=1.2, 95% CI 1.0-1.4), and anticoagulants and antiplatelet drugs (increasing one drug, OR=4.2, 95% CI 2.0-5.2) were risk factors for bleeding complication of tirofiban in elderly patients with ACS. CONCLUSION: Anticoagulants combined with antiplatelet drugs, smoking, age, platelet aggregation and creatinine clearance are risk factors for bleeding complication of tirofiban in elderly patients with acute coronary syndrome.