This study introduces a recently discovered Neolithic culture of insular Northeast Asia. The initial stage of the Kurile Neolithic is described using findings from the 2019–2020 excavations at Kitovyi-2 and -4 on Iturup Island, the Greater Kurile Chain, Sakhalin Region. Several types of Neolithic feature were first revealed on the Kuriles by excavating large areas. The site includes dwellings mostly of two types–terranean with wooden frames that are not dug into the ground, and semisubterranean. Artifacts include linear-relief pottery and retouched bifacial stone tools on flakes and entire singularities, processed by advanced polishing. For the first time on the Kuriles, long barrows encircled by basalt plates along the perimeter were detected. These structures with evidently non-utilitarian enclosures made of plates, tentatively identified as places for cremation burials and funerary rites, indicate symbolic behavior. On the basis of this key criterion, we propose to attribute Kitovyi-2 and -4 to the culture of long barrows. Stratigraphic evidence, supported by radiocarbon analysis, allows us to establish the initial stage of the Kurile Neolithic, dating to 13.0–8.5 cal ka BP.