The sediment distribution in Lake Vättern, which is situated on the southern border of the central Swedish lowlands, is illustrated by a map, in which five main types of sediments are distinguished. Large areas are covered by glaciofluvial sediments with a thin veneer of postglacial silt and sand. Silty mud and gyttja are only found in the deepest parts of the lake, which constitute about 9% of its area. The physical and chemical characteristics of these sediments are discussed on the basis of analyses of six cores from the southern part of the lake. Three of the cores have been palynologically analysed. The dating of one of the cores indicates an average rate of deposition of about 2.5 mm/year for the last 950 years.