The article presents the results of a joint Russian-Tajik geoarchaeological expedition in the middle reaches of the Obi-Mazar River (Republic of Tajikistan). During 2021 fieldwork two Tajikistan Loess Palaeolithic sites were studied: Kuldara (14 pedocomplexes) and Obi-Mazar (7 pedocomplexes). A significant amount of palaeogeographic work was carried out at both sites including sampling for a wide range of geological analyses. At Kuldara, five excavation trenches were established and a small amount of artifacts from pedocomplexes 4 and 5 as well as a few items from PC’s 10 and 11 were collected. Lakhuti IV corresponding to PC 5 was found between the known sites of Obi-Mazar-6 and Lakhuti I. The excavation area was 6 m2 and 2.2 m deep. Archaeological material (662 specimens) was deposited at 8 levels, but can be regarded a single industry. The primary reduction is based on several simple flaking techniques — radial flaking from a single surface, citron and parallel flaking. Some cores were prepared on large and thick spalls; the ventral surface was used as a prepared flaking surface. “Citron flakes” were also found (~ 8 % of the total number of flakes). Not a single blade was discovered. The complex contains roughly equal proportions of scrapers on large spalls, notched-denticulate tools and unifaces. According to the available set of geological data for the Obi-Mazar Valley, PC 5 is dated to ca. 0.5 Ma. The Lahuti IV materials have parallels in the synchronous Early Palaeolithic industries of Tajikistan. A distinctive feature of this site is a very high concentration of artifacts and their occurrence in well-defined cultural horizons, which is recorded for the first time at Loessic Palaeolithic sites.