PURPOSE: This is a retrospective study to analyze the functional results of closed reduction and external fixation of unstable fractures of the proximal humerus. MATERIALS AND METHODS: Ten unstable proximal humerus fractures were managed with closed reduction and external fixation in which other operative methods are not proper due to comminution, osteoporosis or poor general condition of patients. 4 cases of 2-part and 6 cases of 3-part fracture were included. Radiologically union of fracture, malunion and the evdence of avascular necrosis of humeral head were assessed and the functional results were analyzed with Neer scoring system. RESULTS: Radiologically all fractures were healed but in 2 cases malunion was resulted because of reduction loss in proximal fragment. Pin site infection was developed in 7 cases and oral antibiotics were needed. The functional results were excellent in 4, satisfactory in 3 and unsatisfactory in 3 cases. 2 cases with malunion and one case with lack of postoperative cooperation resulted in functionally unsatisfactory. CONCLUSION: External fixation is an alternative method in the treatment of unstable proximal humerus fractures in which open reduction or percutaneous pinning are not proper due to comminution, osteoporosis or poor general condition of patient.