Renin-angiotensin-system(RAS) is one of the most important enzymatic systems in the human body responsible for blood pressure, and for regulation of water and electrolyte metabolism. Angiotensin II (AII) is the final product of the RAS enzymatic cascade. There are several pathways of AII synthesis: classical and alternative. Blockade of RAS provides better results in treatment of arterial hypertension, heart failure and chronic renal insufficiency. AII receptor blockers (ARBs) inhibit the final link of RAS-AII (type1) receptors selectively, have few side effects and are the most effective RAS inhibitors. In some cases, ARBs are recommended as drugs of the first choice. Owing to reimbursement restrictions, ARBs are underused in Estonia.