The safety and effectiveness of continuous epidural fentanyl analgesia (CEFA) in the treatment of blunt chest injury was evaluated by reviewing its use in 40 patients with multiple rib fractures or flail chest. Ventilatory function tests were performed before and after the institution of CEFA and mean changes calculated. The use of CEFA was associated with significant improvement in vital capacity and maximum inspiratory pressure (p less than 0.05). Minute ventilatory volumes and tidal volumes also showed slight improvement. There was no significant change in arterial CO2 tension with the institution of CEFA, and 85% of patients had good pain relief with CEFA. None of these patients required any other narcotic administration. Documented complications associated with CEFA included pruritus, urinary retention, and transient hypotension. There were no major associated complications. The results suggest that CEFA is a safe, effective method of pain control that acts to improve ventilatory function in patients with blunt chest trauma.