This preliminary study was undertaken to determine if surgeons would choose different intervention for lower extremity occlusive disease when given basic clinical information and data from either a duplex scan or arteriogram. Information on degree of stenosis from duplex scans and arteriograms of 29 patients was indicated on an anatomical line drawing along with the ankle blood pressures and a brief clinical description. Based on these data sheets, six vascular surgeons chose a clinical plan in a blinded fashion for each patient. Each plan was placed into one of eight possible categories for comparison using the kappa statistic. Intraobserver agreement between surgeons' decisions based on duplex scanning versus those based on arteriography was very good (mean kappa .70 with exact agreement in 76%). Interobserver agreement between different surgeons' decisions based on the same studies was significantly less (mean kappa 0.56, p less than .05). Significant disparity in clinical approach occurred in 43% of the patients with nearly identical duplex scan and arteriogram reports, suggesting that much of the discrepancy lies in the clinical decision-making process. Clinical decisions made using duplex scans are very similar to those made using arteriograms. This technique can limit the need for arteriography in assessing patients with lower extremity arterial occlusion disease.