Schistosoma haematobium infects school children in areas where the disease is endemic. This study was carried out to determine the reliability of IgG Enzyme-Linked Immunosorbent Assay (ELISA) as an immunodiagnostic tool, using whole antigen derived from Schistosoma eggs. Children of school going age living in Ipogun village, in south western Nigeria; a schistosomiasis endemic community; were used in this study. The sensitivity of the IgG ELISA in detecting positive cases was 68.0% and there was a significant correlation (P < 0.05) between IgG titres and the intensity of infection. However, the specificity was 59.3%, slightly lower than the sensitivity. Results from this study shows that IgG ELISA can be used as a diagnostic tool for determining S. haematobium infection, as it provides an evidence for the intensity of the infection in the infected individuals.