The title compound, (C(7)H(11)N(2))(3)[Nd(2)Cl(4)(H(2)O)(10)]Cl(5)·2H(2)O, consists of three 4-(dimethyl-amino)-pyridinium cations, one of which is disordered about an inversion center, one [Nd(2)Cl(4)(H(2)O)(10)](2+) dication possessing inversion symmetry, five chloride anions, one of which is disordered over two inversion centers, and two lattice water mol-ecules. The 4-(dimethyl-amino)-pyridinium cations are protonated at the pyridine N atoms and form N-H⋯Cl hydrogen bonds with Cl(-) counter-ions. The dimethyl-amino groups (C/N/C) lie close to the plane of the pyridinium rings, making dihedral angles of 1.6 (6)° and 6.5 (3)°. In the crystal, the [Nd(2)Cl(4)(H(2)O)(10)](2+) dications are linked via O-H⋯O and O-H⋯Cl hydrogen bonds, forming sheets lying parallel to the bc plane. These sheets are linked via O-H⋯Cl hydrogen bonds, forming a three-dimensional network. The 4-(dimethyl-amino)-pyridinium cations are located in the cavities and linked to the framework by C-H⋯Cl interactions.