Ventilator-associated pneumonia (VAP) is a common and serious infection in the intensive care unit (ICU), closely linked to the microbial environment in the mouth of patients with mechanical ventilation. Chlorhexidine, a widely used oral hygiene disinfectant, may play a role in preventing VAP. However, in recent years, there has been some controversy surrounding the use of chlorhexidine in oral care. This article summarizes the antibacterial mechanism of chlorhexidine, its role in preventing VAP, the effects of chlorhexidine at different concentrations and frequencies in VAP prevention, as well as safety and bacterial resistance issues, to provide reference for the clinical oral care application and related research of chlorhexidine.

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