ObjectiveTo systematically review the effect of selective oropharyngeal decontamination (SOD) on the prevention of ventilator-associated pneumonia (VAP). MethodsWe electronically searched PubMed, EMbase, CBM, Wanfang, CNKI and Cochrane Central Register of Controlled Trials from the date of its establishment to September 2013. We also hand-searched some relevant references of included studies. Two independent reviewers screened the studies for inclusion, extracted data, and assessed trial quality. Meta-analysis was performed using the Cochrane Collaboration's RevMan 5.1 software. ResultsTen randomized controlled trials involving 2 791 patients were included. Results of meta-analysis showed that, compared with control group, SOD could reduce the incidence of VAP[RR=0.53, 95% CI (0.43, 0.65), P<0.000 01]. No statistical differences between the two groups were found for all cause mortality, average duration of receiving mechanical ventilatory assistance or length of stay in intensive care unit. No severe adverse event related to study participation was identified. ConclusionSOD can reduce the occurrence of VAP effectively and safely. Consequently, it may be considered as a good choice in the prevention of VAP.