Forty cases of arterial popliteal traumas occurring in the course of 1992 were collected by 20 centers. The purpose of this prospective study was to evaluate a pre-operative prognosis score suggested by Crolais from a retrospective study. Five clinical criteria are taken in account to establish the score: delay, degree of ischemia, contusion, general condition of the patient and wound apperture. Each of the criteria is affected by a progressive note according to the gravity. Analysis of our series confirms the seriouness of this pathology: one death, 8 major amputations and 50% of morbidity. The statistical analysis of pre-operative score and post-operative recovery confirms the existence of three groups at progressive risk: Low risk, score < 30 points. Revascularization must be done. Post-operative recovery is simple. Average risk, score is between 31 and 50 points. Revascularization must be done. Post-operative recovery is particularly simple as the delay before revascularisation will be short and systematic fasciotomies will be done. Major risk, score > 50 points. An amputation must be carried out.