This paper presents and interprets two data sets from Vestfold, Southeast Norway: the pollen record is from a small lake basin, isolated from the sea in Mid Mesolithic (8100-6400 cal BC), and with a record of sediment deposition up to recent time. Charred plant remains from six settlement sites ranging in date from the Late Neolithic (2400-1800 cal BC) to the Merovingian Period (cal AD 570-800). Soil from archaeological contexts that was recovered from several prehistoric settlement features (two-and three-aisled houses, a rock shelter and a pit) has also been investigated. The number and concentrations of identifiable charred macro remains are low from all features except one, but the records contribute to the interpretation of agriculture and wild plant use. Carbonised cereals dated to the Late Neolithic/Early Bronze Age are reported from a two-aisled house. Naked barley was the main cereal identified and a few weed seeds were found with the cereal grains. In a rock shelter nearby, cereals and seeds of flax were found, demonstrating cultivation in the Late Bronze Age. Pollen of ribwort plantain recorded in lake deposits in Nordbytjern, 0·5 km to the southwest, also indicates agricultural activity in the southern part of Vestfold during the Late Bronze Age. Archaeobotanical samples from Early Iron Age houses contained low concentrations of carbonised cereal remains, mainly hulled barley, but also wheat and oat. Seeds/fruits of weeds, plants of moist/wet habitats and grasses increase in abundance from the end of Roman Period. The high concentration of hulled barley found in a pit at the site of Ringdal 13 confirms that hulled barley was a cereal used in the Iron Age. Throughout the Iron Age, cereal pollen has a continuous curve in the Nordbytjern pollen diagram, demonstrating the significance of cereal cultivation in Vestfold. Flax was also cultivated in the vicinity of and probably processed in Nordbytjern. Large numbers of rush seeds and sedge nutlets indicate a possible involvement in basketry and cordage making and/or as animal fodder.