Tissue cultures of monkey-kidney cells were used to detect viral agents in extracts of stool specimens from a group of healthy children in southern Louisiana. From approximately 150 children, averaging 6 months of age at the beginning of the study, specimens were collected once a month from January 1954 through December 1955, as part of a larger study of the natural transmission of polioviruses. The agents isolated were divided into two main categories, the polioviruses (including all three types in approximately equal numbers) and a heterogeneous group designated as nonpolio viruses. The latter may have included Coxsackie viruses, ECHO viruses, adenoviruses, herpes simplex, mumps, influenza, and as yet undescribed agents. The percentage of specimens containing these two groups of enteric agents was reported monthly over the two-year period. A marked seasonal association was evident, with a peak in the summer and autumn months. The combined maximum percentage positive was 29.5, in July 1954. An association with socio-economic status was demonstrated; Negroes had the highest rate and were followed in descending order by the white lower economic and the white upper economic groups. No distinct association with family size was noted. It was not possible to attempt to associate disease incidence with virus excretion in general, but no cases of overt poliomyelitis, aseptic meningitis, or serious diarrhea were diagnosed by the physicians of the participating families. The remarkable abundance of these agents was discussed, as well as the difficulty in associating them with clinical disease syndromes.