The head louse infestation had been no problem since 1960s in Korea. However, the present study revealed high infestation rate among the primary school children in Seosan-gun, Chungnam Province in July 1983. The cases of louse positive were determined by identifying the adult worms and/or their llits on scalp and hairs. The overall louse positive rate among 615 children examined was 73.5%. The rate was higher in girls (78.8%) than in boys (67.6%) and was highest in 3rd-4th school grades. It was observed that the more the number of family members the higher the infestation rate of children. The positive children were treated with 20% benzyl benzoate solution after the teat for louscidal effect in petri dish. However, establishment of intensive control measure is needed to prevent further infestation.