The authors evaluate the indications, the hemodynamical aspects, the short and medium term results over their track record of 49 crossover bypass (44 dacron and 5 PTFE grafts) performed between 1981 and 1993. Crossover bypass grafts were mainly inserted for unilateral iliac arterial disease in order to avoid aortic manipulation. This procedure was particularly selected when in presence of: young patients (< 60 years old), high surgical risk, poor run-off, high risk of prosthetic infection, thrombosis and/or infection of orthotopic grafts. 3 ilio-iliac, 27 iliofemoral, 18 femorofemoral and 1 femoropopliteal bypass have been performed. The postoperative resting pressure Index increase was highly significant in recipient limbs. There wasn't perioperative mortality; during the follow up (mean 24.4 months) no amputation of recipient limb was observed. 4 patients died of A.M.I. and 1 of neoplastic disease. Late cumulative patency rate was 81% at 2 years and 67.3% at 3 years. These values rise to 97.2% and 86.1% respectively when considering patients with "ideal" indication (excluding 7 patients operated on for complications of previous bypass grafts and 6 with extremely poor run-off). An accurate evaluation of the lesion topography and haemodynamic pattern of donor and recipient iliofemoral districts are stressed as key points for a correct surgical indication.