Objective To investigate the association of oral chlorhexidine rinse with incidence of ventilator-associated pneumonia (VAP). Methods We searched PubMed as well as references lists from publications to collect randomized controlled trials comparing oral chlorhexidine with placebo in their effects on incidence of VAP. Meta analysis was performed using software Review Manager 5.0. Results Nine randomized controlled trials were included. Oral chlorhexidine rinse resulted in a reduced incidence of VAP (OR=0.44, 95%CI 0.32－0.62). There was no difference in mortality rate between patients receiving oral chlorhexidine rinse and placebo (OR=1.04, 95%CI 0.79-1.83). Conclusion The available evidence indicates that oral chlorhexidine rinse can reduce incidence of VAP.