OBJECTIVEEvidence is lacking on the preventive effect of oral care on healthcare-associated pneumonia in hospitalized patients and nursing home residents who are not mechanically ventilated. The primary aim of this review was to assess the effectiveness of oral care on the incidence of pneumonia in nonventilated patients.METHODSWe searched 8 databases (MEDLINE, Embase, CENTRAL, CINAHL, Web of Science, LILACS, ICHUSHI, and CiNii), in addition to trial registries and a manual search. Eligible studies were published and unpublished randomized controlled trials examining the effect of any method of oral care on reported incidence of pneumonia and/or fatal pneumonia. Relative risks (RR) and 95% confidence intervals were calculated. Risk of bias was assessed for eligible studies.RESULTSWe identified 5 studies consisting of 1,009 subjects that met the inclusion criteria. Of these, 2 trials assessed the effect of chlorhexidine in hospitalized patients; 3 studies examined mechanical oral cleaning in nursing home residents. A meta-analysis could only be done on 4 trials; this analysis showed a significant risk reduction in pneumonia through oral care interventions (RRfixed, 0.61; 95% CI, 0.40–0.91; P=.02). The effects of mechanical oral care alone were significant when pooled across studies. (RRfixed, 0.61; 95% CI, 0.40–0.92; P=.02). Risk reduction for fatal pneumonia from mechanical oral cleaning was also significant (RRfixed, 0.41; 95% CI, 0.23–0.71; P=.002). Most studies had a high risk of bias.CONCLUSIONSThis analysis suggests a preventive effect of oral care on pneumonia in nonventilated individuals. This effect, however, should be interpreted with caution due to risk of bias in the included trials.Infect Control Hosp Epidemiol 2015;36(8): 899–906