Mahanadi is the sixth-largest river basin in peninsular India, providing considerable resources for millions of people through time. This is evident in the high density of archaeological sites spanning the  prehistoric to Early Historic periods that have been identified along the banks of the Mahanadi. Geographically, it appears to have been a significant location for prehistoric human occupation, as reflected in the high density of Paleolithic and microlithic assemblages recorded compared to other parts of India. However, archaeological and paleoanthropological research in this study area has been sparse. This paper discusses the results of fieldwork, GIS mapping, and small-scale archaeological excavations in the Upper Mahanadi basin, as well as lithic analyses on recovered assemblages. The focus will be on the context of sites, lithic technology and raw material usage, site distributions and settlement patterns, the Pleistocene fossil record, and the Quaternary sequences of prehistoric sites in the Upper Mahanadi basin.