Background. Bed rest and immobility in patients on mechanical ventilation or in an intensive care unit (ICU) have detrimental effects. Studies in medical ICUs show that early mobilization is safe, does not increase costs, and can be associated with decreased ICU and hospital lengths of stay (LOS). Objective. The purpose of this study was to assess the effects of an early mobilization protocol on complication rates, ventilator days, and ICU and hospital LOS for patients admitted to a trauma and burn ICU (TBICU). Design. This was a retrospective cohort study of an interdisciplinary qualityimprovement program. Methods. Pre- and post- early mobility program patient data from the trauma registry for 2,176 patients admitted to the TBICU between May 2008 and April 2010 were compared. Results. No adverse events were reported related to the early mobility program. After adjusting for age and injury severity, there was a decrease in airway, pulmonary, and vascular complications (including pneumonia and deep vein thrombosis) post- early mobility program. Ventilator days and TBICU and hospital lengths of stay were not significantly decreased. Limitations. Using a historical control group, there was no way to account for other changes in patient care that may have occurred between the 2 periods that could have affected patient outcomes. The dose of physical activity both before and after the early mobility program were not specifically assessed. Conclusions. Early mobilization of patients in a TBICU was safe and effective. Medical, nursing, and physical therapy staff, as well as hospital administrators, have embraced the new culture of early mobilization in the ICU. © 2013 American Physical Therapy Association.