The title compound, 2C5H7N5(2+)·2HSO4(-)·SO4(2-), was synthesized from adenine and sulfuric acid. The asymmetric unit contains two diprotonated adeninium cations, two bis-ulfate anions and one sulfate anion. The crystal structure is stabilized by classical N-H⋯O and O-H⋯O hydrogen bonds, and weak C-H⋯O and C-H⋯N hydrogen bonds, generating a three-dimensional network.