Hexamethylenetetramine dinitrate (HDN) is a rather weak explosive but is used as a precursor for the synthesis of RDX, one of the most important secondary nitramine explosives. HDN has limited application because of its hygroscopic character. This paper reports on the synthesis and characterization of HDN in high yield and purity by the reaction of hexamine with nitric acid at temperatures below 15 degrees C. It was characterized by FTIR and H-1 NMR spectroscopy, Scanning Electron Microscopy (SEM) and Liquid Chromatography/Mass Spectrometry (LC/MS) measurements. The thermal characteristics of HDN were determined by DSC and TG/DTA. The DSC curve of HDN shows an endothermic peak at 170.5 degrees C corresponding to the melting point of HDN, followed by two exothermic peaks at 174.0 degrees C and 200.5 degrees C due to the decomposition. The differences in the thermal behavior of HDN samples, which were thermally aged at 50 degrees C, 100 degrees C, and 150 degrees C in a nitrogen atmosphere were examined. Additionally, some quantum chemical properties of the nitration of hexamethylenetetramine were calculated.