Between 1986 and 1991, 120 femoral fractures were treated in 116 children. The treatment of choice was conservative in young patients (overhead traction in 1- to 3-year-old children. Weber traction in 3- to 8-year-old children). Operative treatment was indicated in older children: plate fixation was performed in children between 5 and 16 years of age, while external fixation was used in children aged 2-14 years. In a retrospective study 66 femoral fractures in 62 children were reviewed and limb length checked both clinically and by ultrasound measurement. For ultrasound evaluation a special device was constructed to provide standardized measuring conditions. In 27 cases we observed specific complications related to the method. In all cases fracture healing occurred, but in 7 cases it was necessary to change the method of treatment. Ultrasound measurement revealed mean limb lengthening of 5.5 mm after overhead traction (max. 11 mm) and of 7 mm (max. 25 mm) after Weber traction. The median difference in leg length after operative treatment was 5.5 mm (max. 15 mm) for plate fixation and 8.5 mm (max. 25 mm) for external fixation. Our results allow no definitive statement on the most suitable treatment for femoral fractures in children (conservative versus operative treatment), except that children under 3 years of age are best treated by overhead traction.