Levels of serum copper (Cu), zinc (Zn) and magnesium (Mg) were determined in the sera of 250 children aged between 6 and 13. Of these children, 180 were infected only with Enterobius vermicularis. The remaining 70 children were without parasitic or bacterial infection and made up the control group. The cellophane tape method was used to detect E. vermicularis infection. The levels of Cu, Zn and Mg in the serum samples were measured with the Perkin-Elmer 2380 Atomic Absorption Spectrophotometer. Evaluation by the student-t test showed that the means of the Cu, Zn and Mg in the serum were significantly lower in the infected group than in the control group. Thus? in this study, we found that E. vermicularis adversely affects the level of elements such as Cu, Zn, and Mg in serum.