No large prospective data are available on ventilator-associated pneumonia (VAP) in patients with traumatic brain injury (TBI).To evaluate the incidence, timing and risk factors of VAP after TBI and its effect on patients' outcome.and Methods: Analysis of the CENTER-TBI dataset, a large, multicenter, prospective, observational study including TBI patients admitted to European intensive care units (ICU), mechanically ventilated for ≥48 hours, and with an ICU length of stay (LOS) ≥72 hours. Characteristics of VAP vs non VAP patients were compared, and outcome was assessed at 6 months after injury using the extended Glasgow Outcome Scale.962 patients were included. 196 (20.4%) developed a VAP at a median interval of 5 days (interquartile range (IQR): 3-7 days) from intubation. Patients who developed VAP were younger (median age 39.5 yrs. IQR: 30-66 vs. 51 IQR: 25-55, p<0.001), with a higher incidence of alcohol (36.6% vs. 27.6%, p=0.026) and drug abuse (10.1% vs. 4.3%, p=0.009), more frequent thoracic trauma (53% vs. 43%, p=0.014), and experienced more episodes of respiratory failure during ICU stay (69.9% vs. 28.1%, p<0.001). Age (HR=0.99, 95%Confidence Interval, CI=0.98-0.99,p=0.001), chest trauma (HR=1.4,95%CI 1.03-1.90, p=0.033), H2-receptor antagonist intake (HR=2.16, 1.37-3.39,p=0.001) and antibiotic prophylaxis (HR= 0.69, 95% CI 0.50- 0.96,p=0.026) were associated with the risk of VAP. Patients with VAP had a longer duration of mechanical ventilation (median 15, IQR: 10-22, days vs. 8 days, IQR: 5-14, p<0.001) and ICU LOS (median 20 days IQR: 14-29 days vs. 13 days IQR: 8-21 days, p<0.001). However, VAP was not associated with increased mortality or worse neurological outcome. Overall mortality at 6 months was 22%.VAP occurs less often than previously described in patients after TBI and has a detrimental effect on ICU LOS, but not on mortality and neurological outcome.