Background Healthcare-acquired pneumonias are a significant risk for nursing home and hospital patients. While oral care interventions (OCIs) have been found to be effective in reducing the risk of ventilator-associated pneumonia (VAP), their utility in mitigating non-ventilator-associated pneumonias (NVAP) remains unknown. We performed a structured meta-analysis of randomised and non-randomised clinical trials of enhanced oral hygiene procedures on NVAP.Methods We searched PubMed and Embase to include clinical trials (randomised and non-randomised), and observational (retrospective and prospective) and quasi-experimental studies examining the effect of any method of OCI on incidence of NVAP.Results After quality assessment and consensus agreement between authors, we synthesised six randomised clinical trials (3,891 patients), two non-randomised trials (2,993 patients), and separately assessed a retrospective trial (143 patients) and a quasi-experimental study (83 patients). Most studies, performed in nursing homes, did not show a significant association between OCI and NVAP prevention (RR random 0.89, 95% CI 0.64-1.25, p value 0.50). Likewise, the non-randomised trials failed to show an association between NVAP risk and OCI (RR random 1.42, 95% CI, 0.70-2.88, p value 0.32). However, in the subgroup analysis comparing dental professional involvement in care vs usual care, reduced NVAP risk was demonstrated (RR random 0.65, 95% CI 0.43-0.98, p value 0.03).Conclusions Study results suggest that professional dental care may confer some benefit among NVAP patients. The lack of consistent OCI protocols, data in hospitalised patients and robust randomised clinical trials do not allow definitive conclusions about the contribution of OCI in mitigating NVAP risk.