Energetic salts of the 5,5‘-azotetrazolate anion with different guandidinium cations were investigated, including bis(guanidinium) 5,5‘-azotetrazolate (GZT), bis(aminoguanidinium) 5,5‘-azotetrazolate (AGZT), bis(aminoguanidinium) 5,5‘-azotetrazolate monohydrate (AGZTH), bis(diaminoguanidinium) 5,5‘-azotetrazolate (DAGZT), bis(triaminoguanidinium) 5,5‘-azotetrazolate (TAGZT), and bis(azidoformamidinium) 5,5‘-azotetrazolate (AFZT). AGZT was obtained according to the literature as the monohydrate (AGZTH), and DAGZT was synthesized for the first time. All salts were fully characterized by vibrational spectroscopy (IR, Raman), multinuclear NMR spectroscopy, and elemental analysis. Safety testing (impact and friction sensitivity) was performed to find safe handling procedures. The crystal structures of AFZT and AGZTH, which crystallize in the monoclinic space groups P21/n and C2/c, were determined. The thermal decomposition of the salts was monitored by differential scanning calorimetry, and the gaseous products of the explosions of all compounds were identified with mass spectrometry and IR spectroscopy.