To investigate the correlation between the long-term results of an extra-anatomic bypass and operative flow waveform analysis, we retrospectively reviewed 32 axillofemoral and 21 femorofemoral bypasses for between 1 and 5 years after surgical repair. For the grafts with a type O or I flow waveform pattern, the patency at 3 years (83%) and at 5 years (83%) was superior to grafts with a type II flow waveform (69 and 60%). For the axillofemoral bypass grafts with a type O or I waveform, the patency rate was 92% at 5 years. In contrast with the type II flow, the patency rate was 70% at 5 years. For the femorofemoral bypass with a type O or I and a II flow waveform, the patency at 4 years was 67 and 46%, respectively. In cases with concomitant superficial femoral artery occlusion, the flow waveform was type O or I in 23% and type II in 77%. The patency rate at 5 years was 85% for cases with a patent superficial femoral artery, and 51% for an occluded superficial femoral artery (p < 0.05). These results suggest that the long-term outcome of extra-anatomic bypass correlates with the operative flow wave analysis. In addition, good long-term results and an accurate flow wave pattern depend on the distal run-off, particularly the presence of a patent superficial femoral artery.