Atmospheric organic matter, either organic aerosols or dissolved organic compounds in suspended clouds or fog droplets, encompasses a multitude of molecular structures, physical properties, and sources. This complexity constitutes a major obstacle to an improved understanding of atmospheric organic matter chemistry and composition, but also on how atmospheric organic matter affects the climate system, atmospheric processes, and human health. Unfolding the detailed composition and structure of atmospheric organic matter is a truly exciting challenge that offers unparalleled rewards toward a better understanding of its role in various atmospheric processes. This review highlights NMR spectroscopy as a promising tool capable of providing molecular level information on atmospheric organic matter contained in aerosols, rain, and fog water. A major emphasis is given on the wealth of information that is obtainable with solid-state and one- and two-dimensional solution-state NMR methods, and on how these data can be employed for source apportionment in different areas. The limitations of such advanced techniques together with methodological aspects concerning sample preparation are also discussed. Finally, the major challenges ahead for improvement of the current knowledge about the chemical structures of atmospheric organic matter based on NMR spectroscopy are outlined.