Free-living soil nematodes are one of the most widely distributed and abundant groups of invertebrates. Together with microarthropods their biomass and abundance dominate soil ecosystems and to a great extent determine their functioning. A very important group of nematodes are those which feed on bacteria. They regulate the number of bacterial colonies and keep them in a phase of active growth, and therefore intensively influence the decay rate of organic matter in the soil. The typical family in this group is the Plectidae. Its representatives occur in fresh waters, benthos, in litter and soil of forests, among moss and lichen vegetation, and in saprobic media. In moss-lichen, forest litter, and meadow-bog communities they may constitute 10-35% of all nematodes (Nesterov, 1977). Like other groups of free-living nematodes, the Plectidae are poorly studied in Ukraine, with published records of only 15 soil-inhabiting species in the whole country (Nesterov, 1979; Soloviova, 1988). During the last two years, collections were made in West Podillia and in the Crimean mountains. Collections residing in the State Natural History Museum of Lviv, which were made in the Carpathians and adjacent regions, and in West Polissia, were also examined. Twenty species of nematodes of the family Plectidae were recorded. Of these 11 are new for Ukraine: Anaplectus submersus, Plectus aquatilis, Plectus elongatus, Plectus magadani, Plectus silvaticus, Ceratoplectus gracilis, Ceratoplectus lenis, Chiloplectus andrassyi, Chiloplectus loricatus and others. Plectus aquatilis, Plectus magadani, Plectus silvaticus and Ceratoplectus lenis were previously known only from original descriptions. Two species of the genus Chiloplectus (Chiloplectus andrassyi and Chiloplectus loricatus) were noted in mountain areas of the Carpathians and the Crimea. This genus is new for Ukraine. These preliminary results, and the total lack of records from large regions of Ukraine, especially the south and east, suggest that the real taxonomic diversity of this family may be far higher. Some specimens may belong to species new to science.