Background: The benefit of corticosteroids in community-acquired pneumonia (CAP) remains controversial.We did a meta-analysis to include all the randomized controlled trials (RCTs) which used corticosteroids as adjunctive therapy, to examine the benefits and risks of corticosteroids in the treatment of CAP in adults.Methods: Databases including Pubmed, EMBASE, the Cochrane controlled trials register, and Google Scholar were searched to fimd relevant trials.Randomized and quasi-randomized trials of corticosteroids treatment in adult patients with CAP were included.Effects on primary outcome (mortality) and secondary outcomes (adverse events) were accessed in this meta-analysis.Results: Nine trials involving 1001 patients were included.Use of corticosteroids did not significantly reduce mortality (Peto odds ratio [OR] 0.62, 95% confidence interval [CI] 0.37-1.04; P =0.07).In the subgroup analysis by the severity, a survival benefit was found among severe CAP patients (Peto OR 0.26, 95% CI 0.11-0.64; P =0.003).In subgroup analysis by duration of corticosteroids treatment, significant reduced mortality was found among patients with prolonged corticosteroids treatment (Peto OR 0.51, 95% CI 0.26-0.97; P =0.04; I2 =37%).Corticosteroids increased the risk of hyperglycemia (Peto OR 2.64, 95% CI 1.68-4.15; P < 0.0001), but without increasing the risk of gastroduodenal bleeding (Peto OR 1.67, 95% CI 0.41-6.80; P =0.47) and superinfection (Peto OR 1.36, 95% CI 0.65-2.84; P=0.41).Conclusion: Results from this meta-analysis did not suggest a benefit for corticosteroids treatment in patients with CAP.However, the use of corticosteroids was associated with improved mortality in severe CAP.In addition, prolonged corticosteroids therapy suggested a beneficial effect on mortality.These results should be confirmed by future adequately powered randomized trials.