We report the use of elastic stable intramedullary nailing (ESIN) in 123 fractures of the femoral shaft in children. Flexible rods are introduced through the distal metaphyseal area, and the aim is to develop bridging callus. Early weight-bearing is possible and is recommended. There was one case of bone infection and no delayed union. Complications were minimal, the most common being minor skin ulceration caused by the ends of the rods. A surprising feature was the low incidence of growth changes, with a mean lengthening of only 1.2 mm after an average follow-up of 22 months. Compared with conservative treatment, ESIN obviates the need for prolonged bed rest and is thus particularly advantageous for treating children.