We describe the cardiovascular risk factors, clinical presentation, and prognosis in a comparative study of patients with peripheral artery disease (PAD) from the Cohorte des Patients ARTériopathes (COPART) cohort, which includes patients hospitalized for PAD in France. Among the 2514 patients included in the cohort, 189 had PAD before or at the age of 50 years and 2325 had it after. Young patients with PAD had diabetes less frequently (34% vs 46%, P < .001), were more frequent active smokers (58% vs 23%, P < 0.001), had lower high-density lipoprotein cholesterol (HDL-C; 41 ± 14 vs 44 ± 15 mg/dL, P = .026), and had a less frequent family and personal history of coronary heart disease. In a subset of 59 patients whose lipoprotein (a) (Lp(a)) was measured, the Lp(a) levels were higher in the young patients than in the older ones (89.7 mg/dL [9.7-151.3] vs 19.9 mg/dL [3.0-207.9], P = .004). Survival and amputation-free survival was 2.2 times higher (1.5-3.2, P < .001) in the young after 1 year. The onset of PAD before 50 years was associated with active smoking, low HDL-C, high Lp(a), and lower mortality.