Abstract: pathology departments of health centers in the State of Bahrain. 23 counterimmuno electrophoresis with Giardiasis; of test. them were sero-positive Giardiasis is the most common protozoan parasites diagnosed in the In 1982 a sample of 300 persons were parasitologically and serologically examined for intestinal parasites in Al Zinj Area. There were 26 cases in In 1983 all records of stool parasitological examinations in Salmaniya Medical Centre were studied, a total of 9664 records. serologically examined by CIT with 93% postiive. Giardia lamblia amongst the families of infected persons of the above sample was higher than the families of non-infected community based study of 0.006 of the population (2123 persons) of 1981 census shown 189 person (8.9%) with positive stool examination and 221 (10.4%) positive CIT, of whom 23 had been infected previously with Giardia, and 9 had a negative stool examination. The study shows 100% The epidemiological parasitological examination of farmers, sewage, and water samples of the agricultural areas revealed several intestinal explains the possible transmission through contamination of vegetables rather than drinking water. 100 persons from the above records were The incidence of persons. The sensitivity with high specific CIT. and parasites that