The title compound, (C(7)H(9)N(2)O(2))(2)[HgCl(4)], self-assembles into cationic organic bilayers containing the 2-methyl-4-nitro-anilinium cations, sandwiched between anionic inorganic layers built up by the distorted tetra-hedral [HgCl(4)](2-) groups. The organic sheets are inter-linked through weak C-H⋯O hydrogen bonds, while they inter-act with the anionic part via strong charge-assisted N(+)-H⋯Cl-Hg hydrogen bonds. The [HgCl(4)](2-) anions are bis-ected by a mirror plane passing through the metal and two of the chloride ions.