Board thesis at the University of Basrah - College of Medicine discussed the relationship between cytokeratin-81 level and fat infiltration of liver diagnosed by abdominal ultrasound in non-alcoholic fatty liver disease. The thesis presented by the student Doaa Saadi Salem, aims to find the relationship between the level of cytokeratin-81 and the fat infiltration and the level of fibrosis of liver using ultrasound of the abdomen in non-alcoholic fatty liver disease. The thesis concluded that the level of cytokeratin-18 corresponds well with the degree of fat infiltration of the liver, while the degree of fibrosis of the liver is poorly proportional to the degree of fat infiltration.