Abstract. Narzullayev SB. 2022. New data on the vertical distribution of nematode communities in mountain ecosystems of Mount Zarafshan, Uzbekistan. Biodiversitas 23: 3967-3975. New data on the vertical distribution of nematode communities in mountain ecosystems (Mount Zarafshan, Uzbekistan) is the first study on the variation of nematode species and ecological groups in Central Asia depending on altitude gradients. The study's primary purpose was to study the nematode fauna of perennial plants in the highlands and to reveal the formation of nematodes following the ecological characteristics. To achieve the study's objectives, samples were collected from perennial plants and rhizosphere soils growing in mountain ecosystems with a maximum altitude of 2590 m above sea level in 2016-2018. The sample analysis determined that the northern slope of the Zarafshan mountain range consists of 121 species belonging to 8 orders, 35 families and 58 genera. The study area is divided into four vertical altitude zones (upper, middle, lower, and foothills), which differ in climate, relief, vegetation cover and density to understand the formation of mountain nematode fauna. Sixty-four species of nematodes were identified in the upper zone, 93 in the middle zone, 104 in the lower zone, and 79 in the foothills. The nematodes in the fauna were divided into ecological groups such as plant feeders, mycophages, bacteriotrophs, predators and omnivores. The obtained results showed that the species and ecological composition of the nematode community depended on changes in vegetation cover density, soil organic composition and water regime in the height gradients.