Pure diethylamine dihydrogen phosphate was prepared from crude wet-process phosphoric acid (WPA). The prepared samples were characterized by chemical analysis, potentiometric titration, thermal analysis, and X-ray diffraction to show good purity levels comparable to those of the standard samples. The obtained results indicate that the prepared salt could be a suitable source for the phosphate value to produce pure orthophosphates of alkali metals and other important monophosphates.