We present the results of surgical treatment of proximal humeral fractures in a group of 40 patients. The fractures were treated with the angular stable Lockin Proximal Humeral Plate, which is based on the LCP-principle (Locking Compression Plate). The upper part of the plate contains small suture holes for fixation of the tuberosities. Between january 2002 and december 2005, 40 patients were operated using this technique. There were 24 women and 16 men and the mean age of our population was 56.5 years. Clinical and radiological evolution was followed until fracture fracture healing and functional recovery and a Constant-score was taken on a retrospective basis with a mean follow-up of 23.6 months. During follow-up 2 patients died of unrelated causes with their fractures healed and 2 patients were lost because they were living abroad. Fracture healing was uncomplicated in 34 patients (89 %). In 4 patients there was secondary displacement of the fracture: varus displacement in 3 cases and complete loosening of the osteosynthesis in a patient who fell again a few weeks after the first intervention. In this patient a new osteosynthesis with the same device was realised and the fracture healed correctly. In the other 3 cases the fracture healed with some varus alignment and in 1 of these the hardware had to be removed because of intra-articular positioning of some screws after varisation of the humeral head. No secondary displacement of the tuberosities was seen. In one case we had an aseptic necrosis of the humeral head 6 months after the osteosynthesis and this patient needed a shoulder arthroplasty. Another patient had severe chondral lesions of the humeral head but symptoms respond well to medical treatment. Hardware removal was necessary in 8 patients because of subacromial impingement or local tenderness. Reflex sympathetic dystrophy occured in 4 cases. The mean Constant-score was 57.6; when correction was made for age and gender the mean score was 73.0.