An epidemiological study was undertaken to estimate the prevalence of Enterobius vermicularis infection among the primary (and infant) school schildren in Ysngyang-gun, Kyongsangbuk-do. During the period from 2 to 14 December 1983, a total of 2,227 school children in 13 schools were examined one time by means of scotch-tape anal swab technique with a simple questionaire study on perianal itching, enuresis and school record. The results are as follows: 1. The overall egg Positive rate was 64.1% and the rate ranged from 46.6 to 86.7% by schools. 2. The egg positive rates of boys and twirls were 60.5 and 68.0% respectively and the difference was statistically significant (P<0.005). 3. There was noted a tendency of decrease in prevalence by increase of the age of children. 4. It was revealed that perianal itching and school record were significantly correlated with E. vermicularis infection (P<0.05) while not in case of enuresis (P>0.1).