Abstract Pneumonia is the most frequent infection occurring in mechanically ventilated patients in the intensive care unit (ICU). Antibacterial mouthwashes are utilized in many clinical conditions for prophylactic and therapeutic purposes. The mouthwashes most commonly conveyed in the literature, including hydrogen peroxide, sodium bicarbonate, sodium chloride 0.9 %, water, povidone-iodine, and chlorhexidine (CHX). The aim of this review article is to evaluate articles to conclude the best existing evidence for providing oral hygiene to ICU patients receiving MV (mechanical ventilation), discuss considering practical oral washes, and to document a research to improve care interventions used for oral care and critical patients’ outcomes.