Background: Management using femoral-popliteal vein (FPV) of aortic graft infections, failing aortofemoral bypass, and aortoiliac occlusive disease in young patients with a small aorta is now an accepted therapeutic method and is performed frequently at our institution. A high reintervention rate for FPV graft stenosis has recently been reported. The purpose of this study was to determine the incidence of FPV graft failure due to stenosis after neoaortoiliac system (NAIS) reconstruction, and to identify risk factors for this complication. Methods: A review was performed of 240 patients who underwent NAIS reconstruction at our institution between January 1991 and December 2005. All patients were entered into a prospective database and were evaluated for the incidence of vein graft stenosis requiring reintervention, risk factors for stenosis, and the rate and type of reintervention required to assist patency. Patients with occlusion are evaluated and reported, but excluded from detailed analysis. Risk factors assessed included gender, operative features, FPV size (diameter), smoking history, and medical comorbidities. Results: Of the 240 NAIS procedures performed during this time period, 11 (4.6%) patients have required 12 graft revisions (one patient required a second intervention) for stenosis using open and endovascular techniques. Over the same time period, graft occlusion occurred in nine patients (3.8%). This provided a primary patency at 2 and 5 years of 87% and 82%, and an assisted primary patency rate of 96% and 94%. Mean time to revision was 23.5 months (range 5.5 to 83.5 months). Median FPV graft size in the nonrevised patients was 7.8 mm (range 4.0 to 11.4 mm), and 6.4 mm (range 4.7 to 8.7 mm) in the revised group (P = .006). Survival analysis revealed small vein graft size (<7.2 mm), coronary artery disease (CAD), and extensive smoking history as independent predictors of time to stenosis (P = .002, .02, .01, respectively), with multivariable analysis confirming these results (P = .002, .06, .012). Patients with CAD combined with small graft size were found to be at especially high risk for stenosis, with 8/36 (22.2%) requiring revision vs 3/184 (1.6%) of patients without both factors (P < .0001). Conclusions: FPV graft stenosis requiring revision after NAIS reconstruction is uncommon. Risk factors for stenosis include small graft size, history of CAD, and smoking. All patients merit aggressive counseling for smoking cessation, and patients exhibiting multiple risk factors should undergo close postoperative surveillance for graft stenosis. © 2008 The Society for Vascular Surgery.