In situ bypass grafting depends on an adequate ipsilateral greater saphenous vein. To profit from a tapered, valveless conduit in legs without an adequate greater saphenous vein, we routinely used the contralateral saphenous vein non reversed. In some reconstructions to the infrageniculate popliteal and the proximal anterior tibial artery we used the non reversed instead of the in situ technique because of the distance between the natural course of the saphenous vein and the recipient artery. This retrospective study compares the outcome of 48 in situ bypasses to the outcome of 66 non reversed bypasses. Endoluminal manipulations in all veins were visually controlled using an angioscope. The two groups of bypasses (in situ versus non reversed) did not differ concerning age, sex, risk factors, operative mortality, indication for surgery and distribution of the recipient arteries. There was a tendency for a lower wound complication rate in "in situ" compared to non reversed bypasses (10% versus 27%; p = 0.086). There were no differences in cumulative primary and primary assisted patency rates between the two groups after two years. We prefer the angioscopy guided in situ technique for reconstructions to infrageniculate arteries because of a low wound complication rate and excellent patency rates. In the absence of an adequate ipsilateral saphenous vein and in reconstructions to recipient arteries not presenting themselves for the in situ technique, similar results can be achieved with angioscopically prepared non reversed grafts.