The aim of the study was the bioecological study on the role of small rodents (Muridae, Cricetidae) in the transmission of parasitic species in the zoonotic and epizootic chain, within the wet and dry biotopes of natural and anthropized ecosystems. The studies were performed in 2015-2018 in various types of biotopes from the central area of the Republic of Moldova. Plagiorchis elegans, found in investigated small rodents, is a trematode characterized by a cosmopolitan spread and increased incidence in a wide variety of vertebrate animals (amphibians, reptiles, fish, birds, mammals) and invertebrates (insects, mollusks, amphibians). This helminth develops in 3 hosts, following the model of the trixene evolutionary cycle. In the adult stage it parasitizes the small intestine of the definitive hosts (reptiles, birds, bats, insectivores, rodents, carnivores, humans), in the larval stage the digestive tract of aquatic gastropods (Lymnaea stagnalis) as first intermediate hosts, then in aquatic insects (larvae, imago) and crustaceans as second intermediate hosts. In rodents from wet biotopes the level of infections with P. elegans parasite was recorded as follows: in yellow-necked mouse (Apodemus flavicollis) - 12.8%, in wood mouse (Apodemus sylvaticus) - 19.2%, in the stripped field mouse (Apodemus agrarius) - 11.8% and in the bank vole (Clethrionomys glareolus) - 3.8%. The absence of the causal trematode P. elegans in the host species Apodemus uralensis, Mus spicilegus, Mus musculus, Cricetulus migratorius, Microtus arvalis, Microtus rossiaemeridionalis from dry biotopes is due to the absence of ecological conditions (swamps, ponds, streams) specific for the development of intermediate hosts (aquatic gastropods, fish) and complementary ones (aquatic insects, crustaceans), involved in the biological cycle of the parasite.