Iliac endofibrosis is a rare condition caused by chronic wall stress and a subsequent progressive fibrosis that usually affects the external iliac artery. It can present with intermittent claudication and is most commonly found in young athletes without significant risk factors for peripheral arterial disease. We present a case of acute thrombosis of the external iliac artery secondary to endofibrosis in a 38-year-old cyclist and describe the treatment options. For symptomatic patients and in case of long arterial occlusion, the treatment of choice is the surgical resection with autologous vein interposition.