A new "bottom-up" approach for the construction of gold nanostructure assemblies through the use of diacetylene templates at the air/water interface is described. Condensed diacetylene Langmuir monolayers constrain Au nanoparticles (NPs) on the water surface. The Au NPs adopt distinct configurations, including nanowires and "nanoislets", depending upon the properties and molecular structures of the diacetylene monomers. The diacetylene/Au NP films can be transferred from the air/water interface onto solid substrates and further annealed without altering the surface organization, yielding stable organized gold nanostructures.