The detection of heat-labile enterotoxin by two tests (culture on Y1 cells and GM1-ELISA) has been carried out on strains of E. coli isolated in stools of children with diarrheal disease (220 strains isolated in the Pasteur Institute in Yaoundé, Cameroon, and 133 stool specimens selected in Grenoble). This work was undertaken to determine the frequency of enterotoxigenic E. coli in two different populations. In Yaoundé the isolation rate (6%) is not very high in comparison with other developing countries. It should be observed that some strains belong to enteropathogenic serogroups. In Grenoble results confirm the very low frequency of enterotoxigenic E. coli in industrialized countries.