Ramipril is an anti-hypertensive drug, a category of ACE inhibitor that inhibit the actions of angiotensin converting enzyme (ACE), thereby decreasing the production of angiotensin II and decreasing the breakdown of bradykinin. The decrease in an enzyme angiotensin II results in relaxation of arteriole smooth muscle leading to a lowering the total peripheral resistance, reducing blood pressure(BP) as the blood is pumped through widened. Ramipril, a precursor or prodrug, is converted to the active metabolite ramiprilat by carboxylesterase. It is mostly excreted by the kidneys. Its half-life is 3-16 hours and is prolonged by heart and liver failure, as well as kidney failure. The medication used alone or in combination with other medications to treat high blood pressure. The drug is also used to reduce the risk of stroke and heart attack in patients at risk for these types of problems and to improve survival in patients with heart failure after a heart attack. Key words: Ramipril, Ramiprilat, Angiotensin II, Bradykinin, Carboxylesterase, Blood pressure.