The current treatment for uncomplicated rib fractures is the exclusion of associated injuries followed by symptomatic treatment with analgesics. Encouragement of deep breathing is also recommended to avoid secondary or delayed pulmonary complications. The use of circumferential rib belts in treating patients with acute rib fractures has been discouraged because of possible complications from restricted ventilation. A review of the literature revealed no previous clinical studies to support this view. We designed and conducted a controlled, prospective, randomized pilot study to determine if there was any increased morbidity associated with the use of rib belts in the treatment of patients with acute rib fractures. Twenty-five adult patients with radiographically proven acute rib fractures were randomized into two groups. The first group was treated with analgesics and a standard circumferential rib belt (Zimmer Universal Rib Belt). The second group was treated with oral analgesics alone. Patients were contacted by telephone three days after the initial injury and then reexamined 14 days postinjury. Rates of pain resolution, compliance, and delayed complications were determined. Rib belts were not found to significantly reduce the severity of pain. Four complications (one case of bloody pleural effusion requiring hospitalization, two cases of asymptomatic discoid atelectasis, and one case of allergic contact dermatitis) were identified, all occurring in the group of patients receiving rib belts. This pilot study indicates that while rib belts are widely accepted by patients for control of pain, they appear to be associated with an increased incidence of complications. Clinical studies with larger sample sizes will be needed to confirm these findings.