The Cenozoic evolution of the epicontinental North Sea Basin is described on the basis of sequence stratigraphy, comprising analyses of seismic sections, petrophysical logs and biostratigraphic studies of foraminifera, dinoflagellates and calcareous nannofossils. Stratigraphic, palaeogeographic and palaeoecological information from the Danish onshore area is integrated in the study. The deposits are subdivided into 21 sequences, which group into seven informal major units. The sequence boundaries are identified by differences in seismic facies and by seismic onlap, toplap and truncation features. The maximum flooding surfaces are placed at internal downlap surfaces which correlate with high values on the gamma-ray logs. The source of sediments and the direction of sediment transport changed several times during Cenozoic deposition. Transport was mainly from the north during the Late Paleocene and Early Eocene, from the west during the Middle and Late Eocene and from the north and northeast during the Oligocene to Quaternary times. The depocenters of the seven major units are generally located marginally, apparently adjoining the source areas. There is only minor evidence for changes in subsidence rates in the basin. A constant rate is assumed from Paleocene to mid Middle Miocene time. For the remaining part of the Cenozoic time an increased rate is indicated. A tentative relative sea-level curve for the North Sea Basin is proposed. The overall trends of the curve are broadly comparable with the global sea-level curve of Haq et al. (1988). Discrepancies may be caused by differences in the biostratigraphic calibrations. The most pronounced Oligocene sea-level fall is dated as latest Oligocene.