Khuzestan province in the south west of Iran having several seasonal and permanent lagoons which are shelter for domestic and migratory birds including, fish-eating birds. This research study was carried out to find the intestinal helminth parasites of birds in this ecosystem and evaluation of their medically importance with emphasis on heterophyid trematodes. For these reasons, the total of 37 birds including; Himantopus himantopus, Fulica atra, Egretta grazetta, Bubulcus ibis, Ceryle rudis, Vanellus indicus, Vanellus vanellus, Charadrius sp. Calidris sp. and Saher (Local name) were hunted and transported to Ahwaz Health Research Center as alive or freshly dead after having been shot. Helminthes collected as alive or dead and fixed in ethanol or formaldehyde. Parasites were identified using morphometric measurements and morphological descriptions. 24 species of intestinal helminth parasites were found as follow: trematodes (Haplorchis taichui, Haplorchis pumilio, Stellantchasmus falcatus, Centrocestus formosanus. Psiloterma marki, Echinostoma revolutum, Parechinostomum cinctum, Echinochasmus coaxatus, Paramonostomum alveatum, Uvitellina pseudocotylea, Cyclocoelum mutabile, Apharyngostrigea cornu, Cardiocephallus brandesi, Cotylurus cornutus, Pseudostrigea buteonis) and nematodes (Amidostomum fuligulae, Cosmocephalus diesingii, Microtetrameres accipiter, Strongyloides minimus) and cestodes (Gyrocoelia perversa, Infula burhini, Dirorchis tringae, Echinocotyle nitida, Spiniglans microsoma). These results have suggested that, the birds are reservoir for helminth parasitic diseases such as heterophyiasis for man and animals in the areas. These helminthes are reported for the first time in the region.