Two hundred and eleven patients with either a displaced rib fracture with a flail chest or non-flail chest injury with severe chest wall deformity were randomized to receive either operative treatment (n=111) or non-operative treatment (n=100). The primary outcome of this trial was the number of ventilator-free days within the first 28 days of injury. Secondary outcomes of interest included total time on mechanical ventilation, length of stay in the ICU and hospital, surgical complications, and adverse events up to 12 months postoperatively. No significant differences were apparent between the two groups with regard to ventilator-free days, pneumonia, ventilator-associated pneumonia, sepsis, tracheostomy, and empyema. The incidence of death was significantly higher in the nonoperative group. In the ventilated subgroup, surgery was associated with improved length of hospitalization as well as ventilator-free days.