Middle and Upper Palaeolithic human migrations and dispersals throughout Central Asia are usually associated with middle altitudes and mild steppe and forest-steppe environments with herds of large game mammals. However, beginning at least as early as the Middle Palaeolithic, human populations colonized areas of Central Asia typified today by extreme arid climatic and environmental conditions. The Gobi Desert and Gobi Altai Mountains of southern Mongolia comprise one such region. Stratified and exposed Palaeolithic sites there include Tsagaan Agui Cave and a variety of surface occurrences. Combining archaeological material from previous excavation campaigns undertaken in the 1980s and from 1995-2000 with new data obtained in 2021-2022, it has become possible to better understand human dispersals not only in the Gobi Desert, but also throughout Central Asia. The Main Chamber of Tsagaan Agui Cave includes 14 layers: Late (Layer 2) and Initial UP (Layer 3), Late Mousterian MP (Layers 4–5), and Mousterian MP (Layers 6–11). A lithic assemblage recovered from Layers 12 and 13 was described as resembling the Acheulean. The chronology of the cave sediments represents a long-term sequence from the LGM back to the Middle and, possibly, Lower Palaeolithic. Newly generated radiocarbon dates indicate human occupational episodes about 44,000 and 55,000 cal. BP in the Upper and Middle Palaeolithic (Layers 4 and 5); earlier occupation episodes in the cave remain insecurely dated. Tsagaan Agui Cave is the earliest known Middle Palaeolithic site in stratified context in Mongolia and greater arid eastern Asia. As such, the materials excavated there comprise an essential element in decoding the human presence in the region during the Pleistocene. Study was supported by RSF #19-78-10112.