The Neogene to Quaternary sedimentary succession of the southern North Sea Basin, which is generally considered to consist of deltaic sediments, has been studied in an 80 by 170km area off the north-west coast of the Netherlands. The total thickness of the succession here varies from 450 to 1,200m, and is thickest at the southern end of the North Sea Central Graben. The sediments were studied using about 2500km of regional seismic data, 58 commercial well logs and 7 high resolution, site investigation, reflection seismic data-sets, the latter covering areas no larger than 6km². From this database a preliminary litho-stratigraphic scheme for the study area has been constructed. This has been fully integrated with existing, offshore stratigraphic schemes. The limited bio-stratigraphic data available has been used to give age estimates of the units which make up the succession. Only sediments deposited between the Netherlands' Praetiglian and the Waalian stages (late Pliocene to early Pleistocene, 2.5 to 1.4Ma) can be assigned ages with any confidence. The base of the Neogene to Recent succession is marked by an unconformity generated by a minor phase of late Oligocene to early Miocene inversion. The oldest part of the succession is made up of 80m of clay, deposited along the southern end of the North Sea Central Graben axis during the ?early to middle Miocene. Following this, there was a major depositional hiatus lasting from ?middle Miocene to ?Brunsummian (middle Pliocene) times. This hiatus, which is marine, is an important marker horizon in both well and seismic data. Sedimentation resumed in the ?early Reuverian (middle Pliocene) in the north-east of the study area, and gradually expanded westward across the hiatal surface to cover the entire study area by the middle of the Tiglian (late Pliocene, ˜1.9Ma). Outer shelf, clay deposition dominated at first, shallowing to middle/inner shelf, coastal and fluvial sedimentation from the beginning of the Praetiglian onward. After a large transgression in the middle Tiglian, a major regression occurred in the late Tiglian (latest Pliocene, ˜1.8Ma), possibly displacing the sea to the far north-west of the study area. Estuarine and fluvial environments probably dominated the study area from then until the ?mid "Cromerian" (˜0.5Ma). A combination of glacial and marine conditions dominated deposition from ?Elsterian times (0.3-0.4Ma) to the present, resulting in large scale erosion and in very complex depositional architecture for sediments of this age.