Background: Statins may be beneficial in treating acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), but their application remains controversial. Objectives: This meta-analysis of published studies investigated their potential benefit in ALI/ARDS treatment. Methods: PubMed, EMBASE, Google Scholar and Cochrane databases were searched and all randomized controlled trials (RCT) and cohort studies with head-to-head comparison between statin and standard care were included. Results: Three RCTs and six cohort studies were included. Overall, statins treatment had no significant effect on mortality compared with placebo (RCTs: OR = 0.99, 95% CI = 0.72,1.37; cohorts: OR = 0.99, 95% CI = 0.71, 1.37). In addition, ventilator-free days were comparable between the two groups (RCTs: SMD = 0.08, 95% CI = 0.03, 0.19; cohorts: SMD = 0.06, 95% CI = 0.17, 0.29). The one-way sensitivity analysis confirmed the stability of results. Conclusion: The results did not show that statins had effects on mortality and ventilator-free days among ALI/ARDS patients. However, this meta-analysis is limited by the number of RCTs included. (C) 2016 Elsevier Ltd. All rights reserved.