 Ventilator-associated pneumonia VAP is very common in the intensive care unit ICU, affecting 9 to 40 of ICU patients and mortality rates range from 20 to 50 and may reach more than 70 when the infection is caused by multi-resistant and invasive pathogens. The most common pathogens that cause VAP are the Gram- bacteria. Findings indicate that TLRs serves as an important signal in the generation of protective innate responses to bacterial pathogens of the lung and that is required for effective innate immune responses against Gram-negative bacterial pathogens. There is genetic evidence that mutations in TLRs increase the risk of developing nosocomial infections. Understanding the TLR system should offer invaluable opportunity for manipulating host immune responses. 