Pneumonia is the second most common nosocomial infection in the United States and the leading cause of death from nosocomial infections. Intubation and mechanical ventilation greatly increase the risk of bacterial pneumonia. Ventilator-associated pneumonia (VAP) occurs in a patient treated with mechanical ventilation, and it is neither present nor developing at the time of intubation; it is a serious problem--with significant morbidity and mortality rates. Aspiration of bacteria from the oropharynx, leakage of contaminated secretions around the endotracheal tube, patient position, and cross-contamination from respiratory equipment and health care providers are important factors in the development of VAP. Nurses caring for patients treated with mechanical ventilation must recognize risk factors and include strategies for reducing these factors as part of their nursing care. This article summarizes the literature related to VAP: its incidence, associated factors, diagnosis, and current therapies, with an emphasis on nursing implications in the care of these patients.