Background: This study was conducted to determine the incidence, risk factors, and outcome of ventilator- associated pneumonia in patients with pulmonary contusion. Methods: The study was conducted at an urban teaching hospital emergency department with an annual volume of 80,000 patient visits. A retrospective analysis was conducted on thoracic injury patients admitted between Jan 2007 and Dec 2009. Among 122 patients investigated, 30 patients were excluded. Patient data included basal characteristics and information related to development of ventilator-associated pneumonia and ultimate mortality. Statistical methods included the Chi-square test and the Mann-Whitney test. Study data were stored and processed using Microsoft Office Excel 2007 & SPSS 18.0 for Windows. Results: Ventilator-associated pneumonia developed in 46 patients (50%). The patients with ventilator-associated pneumonia were more likely to have a longer duration of hospitalization, longer length of ICU stay, longer duration of mechanical ventilation, a low initial GCS, a higher APACHE II score, and were more likely to require emergency intubation or tracheostomy. Factors associated with mortality included longer duration of hospitalization, longer duration of mechanical ventilation, low intial GCS and the need for dialysis. Conclusions: Ventilator-associated pneumonia in the patients with pulmonary contusion was not relevant to mortality, but was relevant to longer hospitalization, length of ICU stay and duration of mechanical ventilation.