The complications associated with the use of rigid internal fixation in 31 consecutive patients who had undergone a mandibulotomy for the treatment of pathology of the oral cavity or oropharynx were reviewed. Rigid fixation was accomplished with two major types of systems: compression plates and reconstruction plates. Complications occurred in 11 patients (35%) with an average of 1.7 complications per patient. Most complications were minor in nature, and were treated successfully with conservative measures. Patients who had preoperative radiotherapy were more likely to develop nonunion and osteoradionecrosis. Plate exposure was the single, most common complication, accounting for 13% of the complications. No major differences were noted in the complication rates between the two systems.