PURPOSE: Recently, the incidence of humerus fracture not allowing open reduction and internal fixation has been increased with increment of traffic accident and industrial accident. But, there have been a few reports in the use of Ilizarov external fixator. The purpose of this study is to report the authors'experience with Ilizarov external fixation for the treatment of the patients with fractures of the humerus. MATERIALS AND METHODS: From June 1996 to July 1998, we reviewed sixteen patients with humeral fracture who were treated by the Ilizarov external fixator. Three fractures were in the middle third of the shaft; two, in the proximal third; two, in the distal third; seven, in the proximalmiddle; two, in the middle-distal. The fractures that were located within the joint of the shoulder or the elbow were excluded. Five fractures had been open and six had been associated with multiple trauma. Two had been initially treated by open reduction and internal fixation but failed : one, because of infection; the other, because of loss of fixation. We performed the Ilizarov external fixator procedure in the case of soft tissue trauma so severe that internal fixation was impossible, and in the case of the comminution too extensive and severe for internal fixation. RESULTS: The average time to radiologic union was 12.7 weeks. According to Stewart and Hundley's functional assessment system, excellent or good results were obtained in 14 cases. There was no poor result. CONCLUSION: Although the Ilizarov external fixator was a technically demanding procedure, it was a good method comparing with any other operative methods for the treatment of fractures of the humerus not allowing the open reduction and internal fixation.