Red blood cell distribution width (RDW) is a measure of the range of variation of red blood cell (RBC) volume. The RDW-SD (Standard deviation ) is an actual measure of size. Normal reference range of RDW-SD in adult human is 39-46 fL .Liver plays an important role in removing body toxins which affects RBCs ,so liver cirrhosis may affects the RDW. Cirrhosis is a chronic degenerative disease in which irreversible scarring of the liver occurs. It leads to liver failure. Child's score is used as an indicator for liver cell function Portal hypertension is an increase in the blood pressure within the portal venous system .Obstruction to blood flow that occurs in liver due to fibrosis and regenerating nodules reduce flow from the portal veins into the hepatic veins. It also impedes hepatic artery flow from the branches that feed into the sinusoids. This increase in arterial resistance leads to an increase in arterial flow into the portal vein via producing a new anastamosis. The net result of that is an increase in portal vein pressure and dilatation of portal vein. Direct measurement of portal pressure is invasive, inconvenient, and clinically impractical. The Hepatic Venous Pressure Gradient (HVPG) is used to measure portal pressure .Recently, portal vein diameter is used as indicator for portal hypertension .