 The major soil-transmitted helminths STHs, Ascaris lumbricoides roundworm, Trichuris trichiura whipworm and Necator americanusAncylostoma duodenal hookworms are amongst the most prevalent parasites worldwide. An estimated 4.5 billion individuals are at risk for STH and more than one billion individuals are thought to be infected, of which 450 million have significant morbidity attributable from their infection, school-aged children in particular. In this population infections cause stunting of the linear growth, anemia, reduce the cognitive function and contribute to the existing malnutrition. In Jimma Ethiopia, STH are highly prevalent, affecting more than 60 of the children data not published. 