Abstract: AIM To evaluate the efficacy and safety of intracoronary tirofiban on TIMI flow in acute coronary syndrome (ACS) with no-reflow after PCI. METHODS Forty-six ACS patients with no-reflow after stenting were randomized to tirofiban group (intracoronary tirofiban, 10 μg/kg, n=26) and nitroglyceride group (intracoronary nitroglyceride, 200 μg, n=20). Targets to be observed consisted of corrected TIMI frame count (CTFC), TIMI flow at 30-minute post-medication, safety end-points of 2-day post-PCI and incidence of major adverse cardiovascular events (MACE) of 30-day post-PCI. RESULTS The TIMI 3 ratio in tirofiban group was markedly higher than that in nitroglyceride group (65% vs 30%, P<0.05). CTFC showed that the coronary blood flow in tirofiban group was faster than that in nitroglyceride group (72±19 vs 93±22, P<0.01). No significant difference was found in the incidence of MACE of 30-day post-PCI and bleeding events between tirofiban and nitroglyceride groups (4% vs 20%; 12% vs 10%). No thrombocytopenia was observed in the two groups. CONCLUSION The administration of intracoronary tirofiban is effective and safe for ACS patients with no-reflow after PCI.