The title complex, [Nd(C(6)H(6)NO(3)S)(2)(C(12)H(8)N(2))(2)(H(2)O)(3)]NO(3)·4H(2)O, comprises a mononuclear cation, an NO(3) (-) anion and two uncoordinated water mol-ecules; the Nd(III) cation, one coordinated water mol-ecule, and the NO(3) (-) anion each lie on a twofold axis of symmetry. The Nd(III) ion exhibits an NdN(4)O(5) coordination environment comprising two O atoms of two monodentate 4-amino-benzene-sulfonato ligands, four N atoms of the bidentate 1,10-phenanthroline ligands, and three water-O atoms. The coordination geometry is based on a tricapped triangular-prismatic arrangement. The components are consolidated into a three-dimensional network via O-H⋯O, O-H⋯N and N-H⋯O hydrogen-bonding inter-actions.