Two enantiomeric counterparts (l- and d-asparginium cations related by glide planes) are present in the structure of the title compound, C(4)H(9)N(2)O(3) (+)·ClO(4) (-), with a 1:1 cation-anion ratio. The structure is built up from asparginium cations and perchlorate anions. In the crystal, mol-ecules assemble in double layers parallel to (100) through N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds. In the asparginium layers, hydrogen bonds generate alternating R(2) (2)(8) and R(4) (3)(18) graph-set motifs. Further hydrogen bonds involving the anions and cations result in the formation of a three-dimensional network.