During geomorphic reconnaissance of the Lower Cunene River near the reach of Serra Cafema, a significant accumulation of Middle Stone Age artifacts was discovered along the Namibia-Angolan border. The archaeological site is downstream of the Marienfluss-Hartmann Valley and lies along the eastern perimeter of the hyperarid Cunene erg (sandsea). Within the study area, the Cunene River is a bedrock anabranching - mixed bedrock-alluvial anabranching system with a morphology that is strongly controlled by lithology and structure and a hydrology dominated by tropical rainfall in the headwaters. A 5 m high alluvial terrace along the left bank of the perennial river is mantled with a surface lag of cobbles and gravels that includes MSA lithics. More than 30 artifacts are preserved in this open-air context. Finds include quartzite flakes, cores, and Levallois-Mousterian points with varying degrees of edge abrasion and varnish; these appear to be the first Levallois-Mousterian points found in this region of Africa. Since the archaeology of this region is poorly known, these cultural assemblages enable initial correlations across southern Africa. A replicate OSL-SAR date ∼220 kyr provides initial age constraints on a sand preserved within the cobble-boulder terrace fill, and constrains a maximum age for the overlying archaeological assemblage. This is the first MSA site in northern Namibia in direct stratigraphic context with a securely dated unit. The artifact assemblage underscores the importance of riparian corridors in reconstructing hominin behaviours during the Middle Pleistocene, the time frame marked by the first appearance and the dispersal of the modern human species Homo sapiens.