Lipoprotein(a) (Lp[a]) consists of a LDL-particle and an apolipoprotein(a) which is related to plasminogen. The physiological function of Lp(a) is largely unknown, but the clinical effects are well known: high plasma concentrations of Lp(a) correlate with a high risk for atherosclerosis independently from other risk factors. This was shown in several studies for coronary heart disease, stroke and peripheral atherosclerosis. Lp(a) has a special position within other risk factors because of the strict genetic control of the plasma concentrations by the apo(a) gene locus on chromosome 6q2.6-2.7. Studies which doubt this relationship have to be considered sceptically. Recent investigations with genetic markers confirm that Lp(a) is a risk factor for atherosclerotic vascular diseases.