The two benzene rings in the cation of the title compound, C(15)H(18)N(4)O(2) (2+)·2NO(3) (-)·2H(2)O, are almost perpendicular [dihedral angle = 91.6 (2)°]. In the crystal, the components are linked by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds.