The Late Pleistocene and Holocene history of Lake Nikolay on Arga Island, western Lena River delta, is reconstructed using shallow seismic and radio-echo sounding (RES) profiles and sedimentary analyses including granulometry, biogeochemistry and pollen analysis. The main objective of this study is directed to the controversy about a glacial or a periglacial origin of Arga Island and a glacial or periglacial origin of the numerous lakes located in the western part of the Lena River delta. Determining the age and genesis of Lake Nikolay, which is the largest amongst the lakes, might mirror large parts of the history of Arga Island. Shallow seismic profiles (25 km total length) of basin fills and complementing RES profiles (23 km total length) of frozen shallow margins and a transect of sediment cores taken from one of Lake Nikolay's depo-centers to the lake margin provide evidence for lake evolution since Early Holocene time and its existence until modern times. Prior to lake evolution uppermost sediments of the second sandy terrace of the Lena River delta holding Lake Nikolay accumulated at the end of the Late Pleistocene (14,500 to 10,900 yr BP). Sediment properties suggest a fluvial environment with riverbed characteristics. After initial wet ground stages lake basin formation in the sandy environment was established at 7000 14C yr BP due to thermokarst. The onset of the thermokarst processes coincides with the regional Holocene climatic optimum according to pollen analyses. Seismic profiles reveal that under deep lake basins closed zones of unfrozen deposits (i.e. taliks) exist. This interpretation is confirmed by mathematical modeling of talik expansion. In fact, neither geological nor geophysical results are obtained, which support the hypothesis of a glacially caused morphology of the area as deduced from remote sensing techniques according to some authors. The occurrence of massive underground ice proposed by others cannot be proven until now, either.