The cichlids, economically important fish species in the region, were collected along the Negro River (Cichla orinocensis, C. monoculus e C. temensis) and in the Marchantaria Island (C. monoculus) Amazon State and in three reservoirs localized in the Piauí State. In order to verify the occurrence of parasites, gills, nostrils and the intestine were removed and observed by stereomicroscope and the mouth by naked eyes. The observed parasites were isolated and conserved in 70% ethanol for posterior identification. From 96 specimens collected in Negro River, 51 specimens (52%) were parasitized. In the Marchantaria Island from 34 specimens collected, 16 (47%) showed the presence of parasites, and from 50 specimens collected in the reservoirs only 2 (4%) were parasitized. In fish collected in the Amazon State, the grill was parasitized by Ergailus coatiarus, Argulus amazonicus, Acusicola tucunarense and the mouth by Braga cichlae, whereas the species collected in the Piauí State did not show the presence of parasites in the grill, but the occurrence of Procamallanus (Spirocamallanus) inopinatus an intestinal nematode parasite.