In the period from 2/98 up to 6/99, fractures of the proximal femur of 70 patients (phi 79.2 a), were treated with a proximal femur nail (PFN((R))). The aim of this retrospective analysis was to evaluate intra- and perioperative complications. The reports of the operation and the anaesthesia documentation sheets have been worked out, all X-rays have been measured, and evaluated along exactly defined parameters. Problems or complications were found in 18 cases (25,7%). In 7 cases (10,0%) these problems could be solved during operation. The "Z-effect" seen in 5 cases (7,1%) and the "cut-out" of the sliding-hip-screw in 6 cases (8,6%) were the most frequent complications. The main reason was a bad primary reposition in varus with a CCD-Angle less than 125 degrees.