The butane-1,4-diammonium cation of the title compound, C(4)H(14)N(2) (2+)·2ClO(4) (-), lies on a special position of site symmetry 2/m, whereas the perchlorate anion is located on a crystallographic mirror plane. An intricate three-dimensional hydrogen-bonding network exists in the crystal structure with each H atom of the ammonium group exhibiting bifurcated inter-actions to the perchlorate anion. Complex hydrogen-bonded ring and chain motifs are also evident, in particular a 50-membered ring with graph-set notation R(10) (10)(50) is identified.