This paper reviews the wide range of organic-N compounds that have been identified by various analytical methods in water sources. These include free and combined aminoacids, chlorophyll, algal toxins, pesticides, nitrosamines and synthetic aromatic compounds such as dinitrotroluenes. This paper attempts to estimate the potential number of nitrogenous compounds in a single water sample. This number appears too large to allow individual identification of compounds that constitute total organic-N. Review of evidence from spectroscopic and thermal degradation methods indicates that most of organic-N is present as amide functional groups in peptidic material and aminosugars. Includes 26 references, tables, figures.