Fifty-two cases of nerves injuries involving the sciatic nerve or one of its two main branches (tibialis or peroneal nerve), between the sciatic notch and the knee, were treated by nerve grafts or nerve sutures. 26 cases were injured in the thigh. They were treated by 11 nerve sutures followed by good results in isolated lesions, and 15 nerve grafts. In 9 cases nerve loss was short and fascicular graft was possible. Clear cut injuries had satisfactory results. In 6 cases, nerve loss was extensive (> 10 cm), especially after sciatic nerve disruption following femoral bone fracture. There was not enough nerve graft available to repair the entire sciatic nerve. Tibialis nerve repair was chosen to restore plantar sensitivity. A vascular nerve graft of peroneal nerve could restore plantar sensitivity in all cases. 26 cases were injured around the knee and involved the peroneal nerve. In 12 cases the lesion was clear cut, treated in 10 cases with a short fascicular nerve graft, and in 2 cases by a suture. In most of the cases, results were good, better than that those obtained after tibialis posterior transfer. 14 cases had peroneal nerve disruption after a severe lateral sprain of the knee. Nerve damages were extensive and results were poor. Tendon transfer had to be done quite often.