To assess several chemotherapeutic schemes for control of enterobiasis, 738 children in five primary schools in Chunchon, Korea, were studied from May 1994 to June 1995. They were divided into 6 groups by the schemes: treatment of once or twice a year; treatment of positive cases or of whole class students; treatment with or without family members. The overall egg positive rate before intervention was 17.5% out of 789 children. Treating all individuals in a class together with family members of positive cases brought better control efficacy than other schemes (p = 0.000). However, when egg positive rate is less than 30%, treating only egg positive cases also can reduce egg positive rate. The confounding factors for the enterobiasis control in primary schoolchildren were new-comer to a class and familial infection.