The organic component of atmospheric reactive nitrogen plays a role in biogeochemical cycles, climate and ecosystems. Although its deposition has long been known to be quantitatively significant, it is not routinely assessed in deposition studies and monitoring programmes. Excluding this fraction, typically 25–35%, introduces significant uncertainty in the determination of nitrogen deposition, with implications for the critical loads approach. The last decade of rainwater studies substantially expands the worldwide dataset, giving enough global coverage for specific hypotheses to be considered about the distribution, composition, sources and effects of organic-nitrogen deposition. This data collation and meta-analysis highlights knowledge gaps, suggesting where data-gathering efforts and process studies should be focused. New analytical techniques allow long-standing conjectures about the nature and sources of organic N to be investigated, with tantalising indications of the interplay between natural and anthropogenic sources, and between the nitrogen and carbon cycles. ► Organic-nitrogen deposition is globally ubiquitous. ► Geographic patterns can now be seen in the near-global dataset. ► Organic N can be formed through interactions of biogenic and anthropogenic compounds. ► Neglecting organic N in deposition assessments increases critical loads uncertainty Routinely including the organic component of atmospheric deposition (known to be around 25–35% worldwide) would make the understanding and prediction of nitrogen biogeochemistry more robust. This paper makes a preliminary global synthesis based on literature reports.