Our paper investigates soil organic carbon and nitrogen in permafrost soils on Sobo-Sise Island and Bykovsky Peninsula in the north of eastern Siberia. We collected and analysed permafrost soil cores and upscaled carbon and nitrogen stocks to landscape level. We found large amounts of carbon and nitrogen stored in these frozen soils, reconstructed sedimentation rates and estimated the potential increase in organic carbon availability if permafrost continues to thaw and active layer deepens.