We found an unexpectedly high prevalence of Schistosoma mansoni in a village in the Upper Egyptian governorate of Giza. Historically, S. mansoni is endemic in the northern Egyptian Nile Delta rather than in the southern Upper Egypt. This observation was made during an evaluation of a rural health care schistosomiasis surveillance program using a cross sectional survey for S. haematobium and S. mansoni in the village of El-Gezira El-Shakra El-Saf district in the Upper Egypt Giza Governorate. A 10% systematic random sample of households of the village was chosen. All persons in the selected houses were invited to submit urine and stool samples. All students from a primary school were also included in the study. Urine was screened by a polycarbonate filtration method and stool was examined using modified Kato-Katz technique. The prevalence of S. mansoni in the population sample and in the school children was 33.7% and 57.7%, respectively, whereas the prevalence of S. haematobium infection in the population sample and the school children was 7.4% and 10.6%, respectively. The prevalence of infection was highest in the younger age groups, and males were infected more than females. Review of Ministry of Health records showed that both species of vector snails, Bulinus truncatus and Biomphalaria alexandrina, were present from 1991 to 1995, and that B. alexandrina was more abundant than B. truncatus in the canals surrounding this village. The unexpected high prevalence of S. mansoni in this village indicates an urgent need to include training programs for S. mansoni surveillance in the primary health care facilities of Giza and to educate villagers to request examinations for S. mansoni as well as for S. haematobium infection.