Ventilator-associated pneumonia is a common complication in intensive care units, occurring in 9% to 24% of patients intubated for longer than 48 hours. Because of this large disease burden and the resultant attributable morbidity and mortality, there is great interest in accurately diagnosing, treating, and preventing this complication. More severely ill patients tend to develop ventilator-associated pneumonia, and identified risk factors include prolonged mechanical ventilation, reintubation after failed extubation, and a few other clinical variables. The efficacy of diagnostic and preventive strategies is somewhat controversial. Diagnosis by invasive methods requires a considerable commitment of resources but can potentially reduce cost of care; however, mortality benefit from this approach has not been demonstrated. As such, in most institutions, ventilator-associated pneumonia is best diagnosed using traditional clinical criteria. Prompt administration of appropriate antibiotics seems to be the only intervention that alters outcome once the diagnosis is established. Several strategies seem to reduce pneumonia incidence; however, mortality and cost benefits have yet to be convincingly shown.