the last two national surveys on intestinal parasitosis realized in costa rica (1982 and 1996) showed an impressive improvement of intestinal helmintiasis, with rates lower than 5%. nevertheless, this problem is relegated to marginal communities, such as is demonstrated in this paper. stool samples of feces from 76 (56%) of the inhabitants of a squatter settlement near the tiribí river, san josé, costa rica were analyzed by direct wet smears, kato, stoll, and agar culture method to looking for strongyloides. the forty-five percent of the people studied had at least one kind of intestinal parasites. the most frequently found parasites were entamoeba coli (27%), trichuris (18%), ascaris (15%). these data prove that the problem of intestinal parasitosis is ongoing and is masked in national surveys that show a fictitiously low rates for the country.