The authors will highlight the advantages of external fixation in the treatment of open fractures of the leg.The first is stabilisation of the fracture site. It is obtained by using transfixion pins in multiple planes (the ideal being 2 planes between 60 and 90°). With flexible pins, stability is obtained by using multiple pins and fixing them to rings under tension.The second advantage is to allow secondary reduction and encourage consolidation by compression, distraction or dynamisation (according to Ilizarov).The third advantage is to leave the adjacent joint free which is sometimes difficult with epiphyseal and metaphyseal fractures even with the newer fixators. Preserving muscle function is sometimes difficult and depends on pin position.The fourth advantage is to be able to obtain skin cover although the use of flaps may be compromised by the pin tracks.The ideal therefore in open fractures of the leg is to fix the fracture site by pins at a distance from the fracture, to obtain skin cover after the fracture has been stabilised and then complete the assembly of the fixator.