Abstract Despite having at least one major river, the Danube, supplying sediment to the Black Sea, the presence of significant deep-water clastic reservoirs has always been viewed as the major exploration risk. Source to sink concepts have been used examine this risk. Reconstruction of plausible paleodrainage scenarios combined with knowledge of the paleogeography, climate and hinterland geology have been used to estimate paleosediment budgets and provide an assessment of reservoir quality in the basin. Analysis of the basin fill, interpreted from extensive seismic coverage calibrated by wells, allows further refinement of the rates of sediment supply. A forward model of the basin fill has been created that successfully produces a postulated fill matching the observed geometry of the fill of the basin. Our analysis shows that fluvial drainage into the Black Sea from the Oligocene through to the Pleistocene has been dominated by small, local, mountainous hinterland drainage, formed in the many surrounding orogens and volcanic arcs. The resulting sediment supplied is predicted to be of low quality. Likely routes for large long-lived fluvial systems draining the continental shields to the north and west, include many updip sediment-trapping basins on the way to the Black Sea, suggests that sediment entered the basin in volume only in the latest Pleistocene. Therefore the risk of finding large volumes of sandstone in the form of large pre-Pleistocene deep-water fan complexes is high. However, smaller volume locallysourced fan-aprons may be common throughout the pre-Pleistocene succession around the margins of the basin.