Lipoprotein a (Lp(a)) is a strongly genetically determined lipoprotein that resembles in density and size a low-density lipoprotein particle (LDL) to which apolipoprotein (a) is bound. There are several isoforms of Lp(a). There is strong evidence that Lp(a) is an independent risk factor for atherosclerosis and cardiovascular disease. Lp(a) is involved in the pathogenesis of atherosclerosis and has prothrombotic properties. Differences in isoform size and lack of standardization have complicated measurement of Lp(a). Currently, reliable determination of Lp(a) is possible with isoform-independent assays. At present the only options to lower Lp(a) levels are nicotinic acid and Lp(a) apheresis. New drugs with Lp(a)-lowering potential are being developed. There is no evidence from trials as yet that reducing Lp(a) levels decreases cardiovascular risk. Currently the clinical value of Lp(a) as a cardiovascular risk factor is limited. Lp(a) measurement could be of value in selected patient populations.