Lipoprotein(a), or Lp(a), is a distinctive lipoprotein particle linked to various cardiovascular diseases, notably atherosclerosis and aortic stenosis. Much like plasminogen, Lp(a) hinders normal fibrinolysis, leading to increased thrombosis and slower clearance of fibrin debris. It also causes inflammation, oxidative stress, and endothelial dysfunction, contributing to the formation of atherosclerotic lesions. Epidemiological studies have consistently shown that even slight increases in Lp(a) levels correlate with a heightened risk of cardiovascular events. Furthermore, Lp(a) plays a role in aortic stenosis by binding to leaflet valves, accumulating within them, and triggering calcium deposition and nodule formation. These calcium deposits gradually narrow the arteries, impeding blood flow. By raising inflammation and oxidative stress in the valve, Lp(a) accelerates tissue damage and calcium deposition. Traditional lipid-lowering therapies have limited efficacy in reducing Lp(a) levels. However, new treatments using RNA interference and antisense oligonucleotides to decrease Lp(a) production in the liver offer promising prospects for mitigating the risks and managing atherosclerosis and aortic stenosis associated with high Lp(a) levels. As Lp(a) screening becomes more common in healthcare, physicians will be better equipped to assess patients' risk levels and provide tailored treatments. This review aims to examine the role of Lp(a) in the development of aortic stenosis and atherosclerosis.