In the title salt, C(5)H(6)N(5) (+)·C(7)H(8)NO(2) (+)·2ClO(4) (-)·3H(2)O, the 3-carboxy-anilinium and adeninium cations are monoprotonated at the amino group and at a pyrimidine N atom respectively. In the crystal, the components are involved in extensive three-dimensional hydrogen-bonding networks composed of O-H⋯O, N-H⋯O, O-H⋯N, N-H⋯N and C-H⋯O inter-actions. Bifurcated hydrogen bonds are observed between perchlorate O atoms and adeninium cations.