Proximal humerus fracture devascularizing the humeral head may require management by prosthesis. Hemiarthroplasty is a logical attitude in such cases, but analysis of functional results and complications has identified a certain number of risk factors limiting indications. Strict analysis of patient characteristics and of fracture type is an essential prerequisite to deciding against treatment by immobilization or osteosynthesis. Results in hemiarthroplasty are primarily dependent on respecting the rules of the art, which aim at stable anatomic osteosynthesis of the surrounding structures so as to restore normal shoulder function. The critical steps are the adjustment of implant height and retroversion, reduction and fixation of tuberosities and good management of the postoperative course. The recent development of fracture-dedicated shoulder implants should improve results. In elderly patients, when local conditions are unsuitable to hemiarthroplasty, a reverse prosthesis may be used, with an adapted surgical technique. Whatever the type of prosthesis, implantation for proximal humerus fracture is a demanding operation with definitive impact on the functional evolution of the shoulder.