Objective To evaluate the effect of tirofiban on short-term prognosis of elderly patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention(PCI). Methods Totally 325 ACS patients were divided into two groups: Tirofiban group (n = 210) and control group (n = 115). All subjects underwent PCI with drug-eluting stents. Patients in tirofiban group received tirofiban, in addition to aspirin and clopidogrel. Patients in control group received oral administration of aspirin and clopidogrel only. The general data, the rate of thrombolysis in myocardial infarction (TIMI) grade 3 flow immediately after PCI, the in-stent thrombosis incidence, mild and severe bleeding rate, platelet decrease rate, mortality, and incidences of myocardial infarction (MI) and target vessel revascularization(TVR) at 30 days after PCI were compared between the two groups. Results The rate of TIMI grade 3 flow immediately after PCI was significantly higher in Tirofiban group than in control group (99.05% vs 94.78%, P＜0.05). The in-stent thrombosis incidence was lower in Tirofiban group than in control group(0.47% vs 3.47%, P＜0.01). The mortality and incidences of MI and TVR at 30 days after PCI were lower in Tirofiban group than in control group(0.00% vs 2.61%, 0.47% vs 3.47%, and 0.47% vs 1.73%, P＜0.01). The mild bleeding rate was higher in Tirofiban group than in control group, with no significant difference (7.14% vs 4.35%, P＞0.05).The rates of severe bleeding and platelets decrease were not significantly different between the two groups (0.00% vs 0.00%, and 0.95% vs 0.87%, P＞0.05). Conclusion Tirofiban can improve the TIMI grade flow in elderly patients with ACS after PCI. It can also decrease the in-stent thrombosis incidence, mortality, and incidences of MI and TVR at 30 days after PCI, but do not increase the rates of severe bleeding and platelets decrease in these patients. So it can improve the short-term prognosis in elderly patients with ACS undergoing PCI.