The second most important infectious complication in hospitalised patients is pneumonia, and it hits first place in the Intensive Care Unit (ICU). Almost 80% of the episodes of health-care pneumonia happens when patient is under mechanical ventilation, causing ventilator-associated pneumonia (VAP). VAP is associated with the highest rates of mortality in ICU infections, mainly if due to Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA). It also increases days under mechanical ventilation and the length of stay in ICU and hospital. Although all the diagnostic procedures, the diagnosis of VAP is based basically in the clinics: X-ray infiltrates and purulent endotracheal secretions are the cornerstone of the diagnosis. We should evaluate and screen any risk factor for multiresistant pathogens. If we have an early VAP and no risk factors, the majority of empiric antibiotic strategies are useful, but if we have a patient with more than one week under mechanical ventilation, previous antibiotic use, and risk factors for multiresistant pathogens, we should then individualize empiric antibiotic treatment.