<p>Five new peroxosolvates of guanidinium, aminoguanidinium, and diaminoguanidinium salts {Gua⁺Cl^- CH₆N₃⁺•Cl^-•H₂O₂ (<b>I</b>), 2AmGua⁺SO₄^2- 2(CH₇N₄)⁺•SO₄^2-•2(H₂O₂) (<b>II</b>), 2AmGua⁺CO₃^2- 2(CH₇N₄)⁺•CO₃^2-•0.86(H₂O₂)•0.14(H₂O) (<b>III</b>), zwitterionic AmGua⁺-CO₂^- C₂H₆N₄O₂•1.58(H₂O₂)•0.42(H₂O) (<b>IV</b>), and DiAmGua⁺Cl^- CH₈N₅⁺•Cl^-•0.5(H₂O₂) (<b>V</b>)} were obtained and their crystal structures were determined. True aminoguanidinium carbonate derivative <b>III</b> was isolated and characterized for the first time. In <b>III</b>, rare case of bifurcate C⁺-N-H…O₂H₂ was observed. In structures <b>I</b>, <b>II</b>, <b>III</b>, and <b>V</b>, cations are combined in stacks via strong π…π interactions with interplanar distances ranging from 3.008(1) to 3.336(1) Å. In these structures, the H-bonded networks result in formation of a complex 3D-dimensional packings with anions and H₂O₂ molecules fill the space between the cationic stacks.</p>