Purpose: We performed an individual patient data meta-analysis to assess the possible benefits and harms of statintherapy in adults with acute respiratory distress syndrome (ARDS) and to investigate effects in specific ARDS subgroups.Methods: We identified randomised clinical trials up to 31 October 2016 that had investigated statin therapy versusplacebo in patients with ARDS. Individual patient data from each trial were compiled. Conventional two-stage metaanalyseswere performed for primary and secondary outcomes, and one-stage regression models with single treatment–covariateinteractions for subgroup analyses. Risk of bias was assessed using the Cochrane Risk of Bias Tool.Results: Six trials with a total of 1755 patients were included. For the primary outcomes, there was no significanteffect of statin therapy on 28-day mortality [relative risk (RR) 1.03, 95% CI 0.86–1.23], ventilator-free days (mean difference0.34 days, 95% CI −0.68 to 1.36) or serious adverse events (RR 1.14, 95% CI 0.84–1.53). There was a significantlyincreased incidence of raised serum creatine kinase or transaminase levels with statin therapy (106/879; 12.1%) versuscontrol (78/876; 8.9%) (RR 1.40, 95% CI 1.07–1.83, p = 0.015). There were no significant treatment–covariate interactionsin the predefined subgroups investigated.Conclusions: We found no clinical benefit from initiation of statin therapy in adult patients with ARDS, either overallor in predefined subgroups. While there was an increased incidence of raised serum creatine kinase and transaminaselevels, there was no difference in serious adverse events among groups. Therefore, we do not recommend initiation ofstatin therapy for the treatment of ARDS.