Prior studies documented that early fixation of femur fractures results in a decreased incidence of adult respiratory distress syndrome (ARDS), fat embolism syndrome, and pneumonia. This study evaluates the impact of magnitude of injury on pulmonary complications and length of ICU and hospital stays in 339 trauma patients with femur fracture undergoing early (n = 121) vs. late (n = 218) operative fixation. Groups were similar with respect to transfusions, hypotension, and associated injuries, but more patients over age 50 years underwent early fixation. Patients were categorized according to Injury Severity Score (ISS): 1) less than 15 (n = 202), 2) 16-35 (n = 104), and 3) greater than 36 (n = 33). Delayed fixation significantly increased the incidence of pulmonary shunt in ISS (3) patients and of pneumonia in patients older than 50. Late fixation resulted in significantly longer hospital stays in all groups and more ICU days in the ISS (3) group. We believe that early femur fixation should be performed on all patients. Pulmonary complications were decreased and health care costs reduced.