Aim: This study aimed to compare the efficacy and safety between standard and low-dose tirofiban in the treatment of elderly high-risk non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients who underwent percutaneous coronary intervention (PCI).Methods: Ninety-four very elderly (≥80 years) high-risk patients with NSTE-ACS were randomly assigned to the standard myocardial infarction (TIMI) grade flow were assessed. The major adverse cardiac events (MACEs), including death, myocardial infarction, recurrent angina and urgent target-vessel revascularization (TVR), were documented at 7 d, 30 d, and 6 months, and bleeding events were recorded at 7 d.Results: Although a significantly higher inhibition of platelet aggregation was observed in the standard-dose group (P0.05). The rate of MACEs was not significantly different at 7 days (2.1% vs 4.4%, P=0.61), 30 days(6.3% vs 8.7%, P=0.71) and 6 months (14.6% vs 17.4%, P=0.71). Major bleeding events were significantly higher in the standard-dose group (10.4% vs 0.0%, P=0.03).Conclusion: In very elderly high-risk patients with NSTE-ACS undergoing PCI, low-dose tirofiban offered about the same level of protection from major ischemic events that standard doses did, with less associated bleeding.