Since 1988 14 femoral shaft fractures were primarily treated in children using the AO-external fixation technique. In contrast to the patients treated by extension only, early mobilisation and out-patient management of these patients became possible. However the time of consolidation was prolonged, probably due to the rigidity of the unilateral double tube AO-external fixator and consequently the insufficient dynamisation of the fracture. Despite of technical complications having occurred in two patients we will continue to apply this method of treatment for femoral shaft fractures. This because the above-mentioned fundamental advantages of this osteosynthesis. For future use a new system with improved means of dynamisation is in evaluation.