In patients requiring an infrainguinal bypass who have an ipsilateral intact GSV, the choice between the reversed and in situ vein graft should be determined by the operative findings and the site of the distal anastomosis. When the ipsilateral GSV has either been removed or is of poor quality, ectopic autologous vein should be used in most circumstances and certainly for bypass to the infrapopliteal arteries. In reviewing the results of the two types of vein bypass to the popliteal artery, the results of two prospective, randomized studies and recent retrospective, nonrandomized reports suggest that there is no difference in patency rates between the two techniques. When performing a bypass to this level, the surgeon should not routinely use one method, but tailor the operative management to the individual patient. However, when the two bypass procedures to the infrapopliteal arteries were compared, the results of a prospective, randomized study and recent retrospective, nonrandomized reports furnish strong evidence that ISVGs provide better long term patency rates than RVGs. These results favoring use of distal ISVGs in nonrandomized reports are even more impressive, since the in situ technique was often preferentially chosen over the reversed vein method when only small diameter GSVs were available and when the bypass was performed to the distal tibial or pedal arteries. Many vascular surgeons agree with the conclusion that the ISVG is the bypass of choice for infrapopliteal bypass when an intact GSV is available. Although both the in situ and reversed vein techniques provide excellent long term patency rates for infrainguinal bypasses, and the vascular surgeon should be able to adapt this technique and approach for the individual patient, further randomized, prospective studies with extensive follow-up evaluation and a large number of patients are necessary to definitively resolve which technique provides optimal patency rates for arterial reconstruction of the lower extremity.