There is very little information on the origin of loess in the northern Iranian loess plateau (NILP) and along the northern foothills of the Alborz Mountain (NFAM) range. To fill this gap, we present the well-dated particle size distribution (PSD) record from the Late Pleistocene Chenarli loess-paleosol sequence in the eastern northern Iranian loess plateau. We also interpret our data in a regional context and compared with other loess records in Central Asia. The obtained trends from PSD may provide insights into sediment transport pathways or distances from sources, availability of sediment and sedimentation rates. The primary modal PSD at ۴۴ μm for the loess at Chenarli is similar to global primary loess. At Chenarli, U-ratios vary between ۳.۵۲ and ۱.۰۲, which are lower than U-ratios reported for Aghband in northern NILP, but is relatively coarser than loess from Neka-Abelou, Mobarakabad, and Toshan in NFAM. Therefore, the finer PSD of loess records from the NFAM may indicate finer grained loess or loess from a different source compared to Aghband and Chenarli loess in NILP. Additionally, the Marine Isotope Stage (MIS ۵) loess at Chenarli is coarser than MIS ۵ loess deposits at the NFAM suggesting that the scenario where MIS ۵ loess on the NILP was carried hundreds of kilometers from distant source(s) can be excluded. Overall, PSD data suggest a nearby local source for loess in Chenarli since MIS ۶.The coarse loess as at Aghband with a modal PSD around ۵۵ μm has not been detected until today, not even in Armenia, Tajikistan and Kazakhstan. Furthermore, the PSD records of loess at Chenarli, Remizovka (Kazakhstan) and Sarigyugh (Armenia) might imply local topographic influences on dust deposition patterns and may point to provenance and wind direction changes and/or to activation of local sources. In contrast, the fine PSD of loess deposits at Darai Kalon in Tajikistan may suggest that loess was mainly transported by near-surface northerly or northwesterly winds.