The most common soil transmitted helminthic infections(STHI) includes infection with Ascaris lumbricoides, Trichuris trichiura, and Hookworm. Growth retardation, malnutrition, anemia, impaired cognitive function and immunosuppression are main manifestations in children. Even within the developing world, wide differences exist in prevalence rates. The poorest countries have higher levels of STHI than those with a lower incidence of poverty. According to an estimate made by the WHO, the prevalence of A. lumbricoides, T. trichiura and Hookworm in South Asia was 27%, 20% and 16% respectively. Given that the prevalence of STHI in urban slums in Bangladesh is much higher than the other parts of the world and Asia and that there are major health and socio-economic consequences of such infections, it is important that we come up with effective means of reducing the prevalence of such infections. 60-80% of preschool children in urban slums of Bangladesh are infected with these STHI due to poor hygiene . At present deworming at six months interval is recommended but the effectiveness of this regimen of dewormig is questionable.