Background: The efficacy of short-term high-dose atorvastatin pretreatment in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) remains unclear. This meta-analysis was undertaken to assess the efficacy of short-term high-dose atorvastatin pretreatment in patients with ACS undergoing PCI. Hypothesis: Short-term high-dose atorvastatin pretreatment may be beneficial in reducing major adverse cardiac events (MACEs) and improving myocardial blood flow in patients with ACS undergoing PCI. Methods: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically reviewed for randomized controlled trials (RCTs) published up to March 2013, in which short-term high-dose atorvastatin pretreatment was compared with control for patients with ACS undergoing PCI. The primary outcome measure was the incidence of MACEs at 30 days. The meta-analysis was performed with the fixed effect model or random-effects model according to the heterogeneity. Meta-analysis was performed by RevMan 5.0 software (Cochrane Collaboration, Copenhagen, Denmark). Results: Nine RCTs incorporating 952 patients met the inclusion criteria and were included in this metaanalysis. Short-term high-dose atorvastatin pretreatment significantly reduced the incidence of MACEs at 30-day follow-up (risk ratio [RR] 0.39, 95% confidence interval [Cl]: 0.25 to 0.61, P < 0.001) and improved the final Thrombolysis in Myocardial Infarction (TIMI) flow grade (RR 1.08, 95% Cl: 1.02 to 1.14, P = 0.01) compared with controls. There were no significant differences in peak creatine kinase-myocardial band and high-sensitivity C-reactive protein level post-PCI between the 2 groups, though there were favorable trends related to statin use. As to the safety end points, no significant difference was observed in elevated liver aminotransferase level between short-term high-dose atorvastatin pretreatment and control groups (RR 1.36, 95% Cl: 0.67 to 2.74). Conclusions: The use of short-term high-dose atorvastatin pretreatment is safe and significantly improves the final TIMI flow grade as well as reduces the 30-day MACEs in ACS patients post-PCI. This finding encourages the use of short-term high-dose atorvastatin pretreatment as an alternative for ACS patients undergoing PCI, but more high-quality randomized clinical trials are still needed to confirm the long-term efficacy and safety.