Tariana is the only North Arawak language currently spoken within the multilingual linguistic area of the Vaupés River Basin. Long-term interaction based on institutionalized multilingualism between East Tucanoan languages and Tariana has resulted in the rampant diffusion of grammatical and semantic patterns (rather than forms). A complex system of negation in Tariana reflects a combination of genetically inherited and areally diffused patterns. Tariana preserves the Proto-Arawak negative prefix in derivational and nominal negation. Some inherently negative lexemes and the distinction between future and non-future negation in declarative clauses are most likely to have resulted from impact of East Tucanoan languages. I discuss each of the Tariana negators, and then draw a comparison with negation patterns found in related North Arawak languages of the Rio Negro and the adjacent areas. These include the Baniwa of Içana-Kurripako dialect continuum, Piapoco, Guarequena, Warekena of Xié (and its dialects Baniwa of Guainia and the now extinct Yavitero), Resígaro, Achagua, Yucuna, Bahwana and Baré (both extinct). The Appendix contains an overview of negative forms in these North Arawak languages, accompanied by a list of sources.