For operative treatment of proximal humeral fractures minimal invasive techniques reduce the risk of iatrogenic damage of blood supply and periarticular scarring. Reported preliminary results are encouraging. We present our experience achieved with an intramedullary wire fixation adapted from a report of Kapandji in 1989. Between 3/95 and 6/00 29 patients were treated with this technique at our institution. All received early functional treatment. 14 patients (average mean age 56 years at time of trauma) who had a minimum follow up of 24 months (mean 36.4 months) and therefore allowed a preliminary conclusion regarding avascular head necrosis (AVN) were reexamined by use of the Constant Score and x-ray. We examined three unstable 2-part, four 3-part and seven 4-part fractures (5 of them valgus-impacted). The mean Constant Score at follow up was 70 points (31-86 points). We saw one total collapse of the humeral head because of AVN. In one patient the distal end of the wires led to a skin irritation and had to be shortened. We observed no secondary fragment displacement or non-unions. In our hands, this technique offers good results, even in valgus-impacted 4-part fractures of the elderly and allows internal fixation in little displaced but unstable fractures with the benefit of early functional treatment instead of longer immobilization. Based on the experience with intramedullary wiring the previously performed technique using threading wires was abandoned and the indication for primary arthroplasty considerably influenced.