Eighty-seven enterotoxigenic Escherichia coli (ETEC) and 36 non-ETEC strains were examined for the presence of the colonization factors CFAI, CFAII(CS1-CS3) and CFAIV(CS4-CS6). All strains were isolated from cases of diarrhea among children under 12 years of age living in the cities of Ouro Preto (MG) and Paulinia (SP), Brazil. Two ETEC (2,3%) strains from Ouro Preto both producing STa enterotoxin, showed serological positive reactions with a-CFAI antiserum. No positive reactions were found with a-CrAII and a-CFAII antisera, though several strains have shown D-manose resistant hemagglutination with at least one of the following erythrocytes: human, bovine and chicken.2511115