The noninvasive vascular laboratory has a great potential to influence patient care if it can offer predictive information, which significantly adds to the clinical and angiographic assessment. To evaluate such preoperative data, 80 patients (143 symptomatic limbs) who underwent aortofemoral bypass were re-evaluated one to seven years following surgery. Preoperative vascular laboratory data (segmental pressure profile, quantitative Doppler velocity indices, postocclusive reactive hyperemia and toe pulse reappearance time [TPRT], following a four-minute cuff occlusion), angiography and clinical status were compared with the postoperative symptomatic result. Overall, 27% of the limbs were asymptomatic, 56% of the limbs markedly improved, 7% of the limbs remained unchanged or worse, and 10% of the patients died. Computer analyses of all preoperative data yielded several significant predictive indices, of which the most sensitive was the TPRT. With a TPRT of 0-10 seconds, all patients became either asymptomatic (63%) or markedly improved (37%). With increases in the TPRT, the results worsened, in stepwise fashion. Combinations of pressure and reactive hyperemic indices also permitted successful predictions in patients with multilevel disease. Such preoperative information can play a significant role in identifying the relative risks and benefits of surgery, and may significantly influence the decision for surgery in borderline situations.