Popliteal artery aneurysms are not so clinically frequent but are the most common site of peripheral aneurysms. They usually affect men aged over sixty and are caused by atherosclerosis. Whenever they concern younger men, other more unusual aetiologies such trauma, infection, inflammatory arteritis or popliteal entrapment are responsible. The authors report the first written observation of small size popliteal aneurysm, revealed by intermittent claudication in a 33 years old subject, of which the origin is accelerated atherosclerosis. The evolution after resection of the popliteal aneurysm and end-to-end anastomosis with saphenous vein was favorable. This observation reminds us of various popliteal aneurysm aetiologies, not excluding atherosclerosis due to young age and also underlines that the small size of these aneurysms does not protect against embolism risk.