BackgroundEndovascular therapy (EVT) is often performed for diffuse femoropopliteal lesions. This study investigated 3‐year patency and clinical outcomes in patients with EVT‐treated femoropopliteal lesions >25 cm.MethodsThis retrospective multicenter registry analyzed patients who presented with lower extremity artery disease having femoropopliteal lesions >25 cm who underwent EVT between 2017 and 2021. The primary outcome was restenosis 3 years after EVT.ResultsOverall, 504 patients with 614 lesions undergoing EVT for diffuse femoropopliteal lesions were enrolled. The prevalence of restenosis was 184.3 per 1000 lesion‐years. Kaplan–Meier estimate of freedom from restenosis was 58.6% at 3 years. In the multivariate Poisson regression model, female sex (adjusted incidence risk ratio: 1.54; p = 0.003), cilostazol use (0.44; p < 0.001), revascularization history (1.87; p = 0.001), P3 involvement (2.09; p < 0.001), and reference vessel diameter <5 mm (1.88; p < 0.001) were associated independently with restenosis risk. The accumulation of these factors was associated with a lower rate of freedom from restenosis; the Kaplan–Meier estimates of the rates were 49.3% and 22.4% in the subgroups with two and more risk factors, respectively, while they were 81.1% in patients without any risk factors and 70.3% in those with one risk factor.ConclusionsFemale sex, nonuse of cilostazol, revascularization history, P3 involvement, and small vessels were associated with high restenosis risk after EVT for diffuse femoropopliteal lesions. Although patients with multiple risk factors have a low patency rate, EVT offers an acceptable patency rate for those with fewer risk factors.