A survey of intestinal helminth parasites among school pupils was undertaken in five primary schools in Iragbiji Local Government of Osun State, South western Nigeria between April and June 2002. A total of five hundred and thirty-three faecal samples were randomly collected from pupils of both sexes whose ages ranged from six to seventeen years old. Using the direct and egg floatation techniques to process the faeces, 402 (72.0%) of the samples were found positive for various intestinal helminths with
Ascaris lumbricoide
accounting for 46.0%;
Ancylostoma spp (Hookworm) 20.5%;
Strongyloides stercolalis
0.6%;
Fasciola hepatica
0.6%,
Trichuris trichuria
0.2%;and mixed infections of Ascaris and Hookworm 1.9%. Sex and age factors did not affect the pattern of infection since the parasites were found in both sexes and all age groups but with varying degrees. Infections were detected in all the schools investigated with one particular school recording infection rate of 100%. The study shows that school pupils carry heavy intestinal parasite burden, which is an index of the prevailing unhygienic environment.