Abstract New evidence from the Ayodhya Hills, located in the western upland of West Bengal, has expanded knowledge of Late Pleistocene microlithic technology spanning 42–25 ka in South Asia. Continuous exploration for the past two decades has resulted in substantial information on technology, distribution of sites and the colluvial context. It is now clear from surface exploration and excavations that there are localized differences in the formation of the colluvial context. At the Mahadebbera and Kana sites, which have yielded optically stimulated luminescence (OSL) dates, the in situ occurrence of artefacts in the excavated sections confirm their association with the colluvial context. The occurrence of microliths for a prolonged period (25–34 ka) at Mahadebbera indicates that the colluvial deposition must have followed a slower rate during the course of occupation at the site. At Khududih-Chauniya, a site currently being investigated, excavation and surface exploration indicate that the artefacts are mostly scattered over the regolith surface capping the bedrock; much of the colluvial material from the site has been eroded and transported downslope, exposing the lithic artefacts over the regolithic badland surface. Added interest in this site ensues from recent finds of Middle Paleolithic cores and a Lower Paleolithic core from the badland rain gullies. This promises to complement the already published results from the region, which has emerged as an important zone in understanding the behaviour patterns of anatomically modern humans in South Asia.