There is no consensus on the best way to treat complicated fractures of the proximal humerus. We treated two-part surgical neck fractures which were not suitable for conservative method by semi-open reduction and Ender nailing with addition of cancellous bone graft. This method provided good three-point fixation and then early ROM exercise was possible even in case of osteoporotic or severely comminuted surgical neck fractures. Between June 1989 and February 1992, Ender nailinss were performed for two-part surgical neck fractures, and among those cases 16 were followed for more than 1 year. The results of study were as follows ; 1. All cases were treated by seml-open reduction and Ender nailing with additional cancelous bone graft. 2. Ender nails were inserted through retrograde entry in all cases. 3. Complications developed in 3 cases ; one case of proximal migration of Ender nail and two of shooter joint partlal stiffness. 4. The mean duration of radiologic bone union was postoperative 9 weeks. 5. According to Neer criteria 11 cases were good, 3 fair and 2 poor results.