A parasitological study was carried out on 381 apparently healthy subjects from Camiri, Boyuibe, Gutierrez. Intestinal parasites and non-pathogenic protozoa were present in 78.7% of the population sampled; multiple infections were observed in 67.7% of the parasitized individuals. The protozoon most commonly found was Entamoeba coli (in 40.7% of specimens), followed by Giardia intestinalis (30.7%), Iodamoeba bütschlii (10%), Chilomastix mesnili (8.7%). Other protozoon parasites also present were Enteromonas hominis (3.4%), Retortamonas intestinalis (2.4%), Cryptosporidium (2.1%), Endolimax nana (2.1%), Balantidium coli (1.8%) and Pentatrichomonas hominis (0.8%). The helminths observed were hookworms (28.6%), Trichuris trichiura (19.7%), Ascaris lumbricoides (9.7%), Hymenolepis nana (8.7%), Trichostrongylus (5.5%), Strongyloides stercoralis (1.8%), Taenia (5 cases) and Enterobius (6 cases). Prevalence for nematodes is probably underestimated in the 3-9 years age group because of a mebendazole treatment given 5 weeks before the survey, under a Program of P D C of the Ministry of Health. The sample from Camiri was found to be the most parasitized (84.1%). An extraordinarily high infection rate was found in two urban institutions, as well as in Itanambicua, a rural community close to Camiri. No significant differences were observed in parasitic prevalence between rural and urban environments. Exposure to contamination with human and animal faeces, overcrowding and poor sanitation habits are some of the factors responsible for the parasitic situation evidenced.