Background: Although in clinical practice endovascular therapy (EVT) with a nitinol stent for femoro-popliteal artery (FPA) lesions has been widely applied for TASC II A/B lesions, primary patency beyond 2 years remains unknown, as do the factors associated with restenosis. Methods and Results: A prospectively maintained database that included 189 limbs treated with nitinol stents for de novo TASC II A/B FPA lesions was retrospectively analyzed. The outcomes were overall primary and secondary patency during the follow-up period and predictors associated with restenosis. Primary patency overall with nitinol stents was 84%, 82%, 80%, 80% and secondary patency was 96%, 93%, 90%, 90% at 12, 24, 36, 48 months, respectively. Primary patency was not statistically different between the 2 types of nitinol stents (Luminexx vs S.M.A.R.T. Control. stent, P=0.37) during follow-up period. From the multivariate analysis, administration of cilostazol was the strongest independent factor associated with restenosis (P=0.0012). Conclusions: Nitinol stent implantation for TASC II A/B FPA lesions is suitable and durable in sustaining freedom from restenosis through 4 years of follow-up. (Circ J 2009; 73: 2143-2147)