Atmospheric organic nitrogen (AON) is an important nitrogen component with significant deposition to many natural waters. The range and quality of the data are varied, but deposited organic nitrogen (DON) is ubiquitous globally, both in extent and magnitude. The Environmental Protection Agency's Chesapeake Bay Program (CBP) sponsored a workshop 20-21 May 1998 at the University of Maryland (College Park). The purpose was to (1) determine the current knowledge of organic nitrogen in atmospheric deposition, and (2) establish research priorities needed to obtain an adequate database for coastal waters such as Chesapeake Bay. Workshop participants concluded that both the abundance of organic nitrogen in the atmosphere, and its proportional deposition is likely to have an effect on aquatic ecosystems. However, knowledge is deficient in the most critical areas, including the nature of atmospheric speciation, transformation, scavenging, sampling, analysis, and ecosystem response. This deficit can only be addressed by the careful design and execution of fundamental research in these areas, such as developing stable isotopic tools and adequate analytical methods, and designing joint intercalibration and field exercises.