The aim of this study was to assess intraoperative transit-time volume flow measurements (VFMs) as a tool for intraoperative evaluation of lower extremity arterial bypass grafts and to predict their patency. We analyzed 273 consecutive patients who had an infrainguinal bypass procedure using the great saphenous vein from 1998 until 2008; 103 had an intraoperative VFM. All intraoperative revisions were recorded and analyzed. Patency and revision rates were compared between those receiving and those not receiving intraoperative VFM. Cox regression was used for analysis of predictors of patency. Primary patency at 1 and 2 years was 75 and 67%, respectively, in patients receiving intraoperative VFM versus 72 and 69% in those without VFM (p = .79). In the VFM group, 12% had an immediate revision versus 6% without VFM (p = .06). In the VFM group, 4% underwent revision to salvage the bypass within the first postoperative 30 days versus 6% without VFM (p = .32). Patency was not associated with the use of VFM. Receiver operating characteristic curve was significant for occlusion at 30 days postoperatively but with a low predictive value (p = .019,area under the curve 0.648). VFM may be helpful in selecting bypasses requiring immediate revision to prevent postoperative occlusion. The use of VFM is not significantly associated with patency.