Microfossil (pollen and diatom) evidence is presented from sites in the Forth valley, south-central Scotland, where alternating organic and estuarine minerogenic deposits record the influence of the changing Holocene sea level. Radiocarbon dating confirms the age of the Main and Low Buried Beaches, and of the Main Postglacial Transgression, in different parts of the Forth valley. Radiocarbon dates on shells from beds in the carse sediment and a Mesolithic shell midden near Grangemouth relate to the falling sea level in the 4th and 5th millennia BP. Sea-level curves are constructed for the western and eastern Forth valley.