Ten discrete types of bottom echoes are recorded and mapped in the Norwegian—Greenland Sea using 3.5-kHz echograms; eight of these are similar to echo types mapped previously in the equatorial Atlantic. The two other types (IA-2 and IC) have not been previously observed and apparently are recorded from bedforms created by deposition and/or erosion by glaciers or ice shelves. A qualitative correlation is observed between the relative abundance of coarse (silt, sand, gravel), bedded sediment in piston cores and three types of echoes. Distinct echoes with continuous subbottoms (IB) are recorded from regions containing little or no coarse sediment; regions of semiprolonged echoes with intermittent zones of subbottoms (IIA) contain low to moderate amounts of coarse sediment; and very prolonged echoes with no subbottoms are returned from regions with high concentrations of coarse sediment. The areal distribution of these three echo types indicate that only low to moderate amounts of coarse, bedded terrigenous sediment occur within the upper few meters of most of the Norwegian—Greenland Sea floor. The types and extremely limited areal distributions of hyperbolic echoes suggest that large-scale contour-current activity has not been an important sedimentary process on a regional basis. This conclusion is further supported by bottom photographs and piston cores which generally show tranquil bottom conditions at present, and an absence of contourite deposition during the Late Quaternary. The only regions where strong current activity is observed are along the top and southern flank of the Faeroe—Iceland Ridge and in the Denmark Strait where the Norwegian Sea Overflow Water flows out of the Norwegian Basin and sinks into the Atlantic Basin. The echo character, as well as most piston cores, show that deposition of terrigenous sediment throughout the Norwegian—Greenland Sea has been mainly by downslope processes (turbidity currents, slumps and related mass flows) and by ice-rafting. Glacial/interglacial climate fluctuations apparently control the influx of terrigenous sediment. During glacial phases the combination of lowered sea level, total ice cover of the Norwegian—Greenland and Barents seas, and widespread continental glacier build-up permitted large amounts of terrigenous sediment to be transported to, and deposited in, the deep basins. In contrast, during interglacials (such as the present), the absence of sea-ice cover and continental glaciers, plus the high sea level which inundated the continental shelves, greatly reduced the quantity of terrigenous sediment reaching the deep basin.