Currently available intramedullary devices for the treatment of unstable pertrochanteric femoral fractures are technically demanding and show a considerable failure rate due to their massiveness and the persistent rotational instability of the head-neck fragment. The Arbeitsgemeinschaft für Osteosynthesefragen (AO/ASIF) therefore designed a new intramedullary device, the proximal femoral nail (PFN), which during a handling study was tested in 4 European clinics. Within one year 191 proximal femoral fractures were treated with the PFN. After a follow up period of at least 4 months technical failures (poor reduction, malrotation or wrong choice of screws) were seen in just 4.6% of the cases. One patient showed a cut-out of the implant but there were no mechanical failures (bending, breaking of the implant) or ipsilateral fractures of the femoral shaft at the tip of the implant. It is therefore concluded that the results of this new implant compare favourably to the currently available implants for the treatment of the unstable pertrochanteric femoral fracture.