Marine debris is a recognized global ecological concern. Increasing numbers of quantitative studies worldwide are investigating litterdistribution and its influence on deep habitats (50–7000 m depth), but little is still known about the extent of the problem. Anthropogenic and environmental factors influence the distribution of debris that enters the seas from both land-based and marine sources. Debris can be displaced for long distances by wind and currents before sinking and can converge in accumulation areas, such as canyons. Plastics typically comprise 50%–80% of debris, due to their wide use and high resistance to degradation. Plastic-related-fishing debris are typical in rocky habitats (≈ 70% of items), which traditionally are subject to intense fishing effort. The widespread presence of debris is strongly impacting deep-water organisms and habitats worldwide. Standardized approaches and specific conservation measures are needed in order to protect unique deep-sea ecosystems that are progressively under threat.