The nonoperative management of patients with Types II and III fractures of the odontoid process consists of a prolonged course of cervical immobilization. The need for rigid fixation, demonstrated by the routine use of the halo vest in many institutions, has never been rigorously substantiated. We retrospectively analyzed our results with the nonsurgical management of odontoid fractures to ascertain whether cranial fixation affected overall outcome. Fifty-four patients managed at the University of Virginia Health Sciences Center, Charlottesville, VA, between 1976 and 1994 were studied. All 18 patients with Type III fractures (5 treated in the collar, 18 in the halo vest) demonstrated fracture healing and late stability. Among 36 individuals with Type II fractures, 20 were treated in the halo vest and 16 were managed in the Philadelphia collar or similar orthoses. The overall rate of late surgical intervention, the stability to flexion and extension, and the rate of bony fracture healing were not statistically different between the methods of immobilization. The rate of bony union was not significantly higher in the halo vest group (74 versus 53%), even though patients managed in the Philadelphia collar were significantly older than those in the halo vest (mean, 68 versus 44 yr). In general, nonsurgical management of Type III odontoid fractures was recommended, accompanied by use of a cervical orthosis. The determination of operative versus nonoperative treatment for Type II fractures was made on the basis of fracture anatomy, patient age, other associated injuries, and patient preference. The lack of a significant difference in the need for late surgical procedures or late instability, improved patient comfort with the cervical orthosis, and elimination of the risk of halo-related complications favored the use of the rigid cervical orthosis in the majority of these cases.