Despite many advances in the treatment of ventilator-dependent patients cared for in ICUs, ventilator-associated pneumonia remains a frequent complication leading to mortality and morbidity. Over the past year, many important articles have been published dealing with the critical question of the relationship between the severity of underlying disease and the occurrence of ventilator-associated pneumonia and death. Pneumonia is the ICU-acquired infection that most frequently leads to mortality and has a poorer prognosis when it is caused by multiresistant bacteria, including gram-negative microorganisms such asPseudomonas aeruginosaorAcinetobacterspp or methicillin-resistantStaphylococcus aureus. This pejorative prognostic effect is stronger in patients with an intermediate level of severity of illness, and this risk increases with prolongation of the ICU stay.