After having reviewed the historical background, the author presents the different applications of microsurgery in orthopaedics and in traumatology: nerve microsurgery (nerve sutures and grafts, neurotizations) and vascular microsurgery (vascularized bone grafts, free muscular flaps, free fascio-cutaneous flaps, replantations). Microsurgery is now part of the therapeutic arsenal of the orthopaedic surgeon.