This study was include collection of 40 stool samples from people were suffer from steatorrhea and the genral stool examination for these stool samples showed the presence of the intestinal parasite Giardia lamblia the etiologic agent of giardiasis . Blood samples were collected from 60 individual 40 of them were the infected with Giardia lamblia patients and the other 20 were healthy and used as control ,then the serum was obtained from all blood samples in the field of the study and the estimation of total (Cholesterol ,Triglyceride ,High density lipoproteins, Low density lipoproteins and Very low density lipoproteins )was done . the result showed that the cholesterol levels were decreased in giardiasis patients while the other types of lipids were normal in the same patients because Giardia lamblia consumed the cholesterol of the host in the bio synthesis of the cell . because the parasite is unable to synthesize cholesterol by itself.
