Two hundred and thirty nine children (114 boys and 125 girls, aged 6-12 years, infected with Enterobius vermicularis worm (E.v.) were selected from 637 originally examined children (329 boys and 308 girls)., derived from El-Katta village, Giza Governorate. The diagnosis was made according to history, physical examination, urine and stools examination, as well as peri-anal swab. The physical growth of these children was investigated by taking some anthropometric measurements which included body weight, standing height, head circumference, upper arm circumf., and triceps skinfold thickness. I.Q. was determined by using Goodenough "draw-a-ma" test. Blood hemoglobin concentration was also determined using a spectrophotometric method. The prevalence of Enterobius vermicularis among our original sample was 43.8%. Mean I.Q. of Enterobius vermicularis infected children was statistically lower than that of their non-infected peers (t = 2.02, P = 0.04), while the non-infected peers (t = 2.42, P = 0.02). Infected male children showed significantly lower I.Q. than infected females (t = 2.02, P = 0.04) while the non infected children showed no sex difference. However physical growth and hemoglobin concentration of Enterobius vermicularis infected children were not statistically different from those of the non-infected control peers, in all age and sex subgroups.