Objective To evaluate the clinical efficacy and safety of nicorandil injection for preventing slow-flow/ no-reflow phenomenon after coronary stent implantation. Methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2009), PubMed, MEDLINE, EMbase, CBM, CNKI, VIP, Wanfang database, etc. from their inception to April 2009. Some relevant journals were handsearched as well. Two reviewers independently evaluated the quality of included studies and extracted the data. Meta-analysis was performed by RevMan 5.0 software. Results Seven randomized controlled trials (RCTs) involving 630 patients were included. The results of meta-analyses showed that intracoronary and intravenous nicorandil could reduce the incidence of no-reflow/ low-flow, reduce Corrected TIMI Frame Count (CTFC), and improve left ventricular ejection fraction (LVEF). Intravenous nicorandil could reduce the incidence of ventricular tachycardia/ventricular fibrillation (VT/VF), pericardial effusion, heart failure, but couldn’t reduce the incidence of death and recurrent myocardial infarction (MI) death. Conclusion Evidence shows that intracoronary nicorandil could prevent no-reflow/ slow-flow, reduce CTFC, improve LVEF, and reduce adverse reaction in patients after coronary stent implantation. However, there is a moderate possibility of selection bias, performance bias and publication bias in this review because of the small number of the included studies, which weakens the strength of the evidence of our results. More large sample size, high-quality RCTs are needed.