one hundred and ninety eight children of a rural village school were studied for parasitological variables, nutritional status (anthropometric variables and blood parameters) and assessment of their learning capacity. the study was designed as a baseline study and included both massive anthelminthic treatment and follow-up of the reinfection process. the initial prevalence of infection by soil helminths was: ascaris lumbricoides 36,4 %, trichuris trichiura 34.8%, hookworm 18,2 % and strongyloides stercoralis 4,5 %. 53,1 % of children were under risk of malnutrition and the values of hematocrit and hemoglobin concentration were below normal in 83 % and 55 % respectively. an important deficit in all the learning capacity tests was observed. some relationship was found between these results and infection by parasites.