In the title compound, {[Ag(2)Gd(C(6)H(4)NO(2))(4)(H(2)O)(2)]NO(3)·H(2)O}(n), the Gd(III) ion is coordinated by eight O atoms from six isonicotinate ligands and two water mol-ecules in a distorted square anti-prismatic geometry. Two Ag(I) ions are each bonded to two N atoms from two isonicotinate ligands in a linear or bow-like fashion [N-Ag-N angles = 178.6 (2) and 147.1 (2)°]. These metal ions are connected by the isonicotin-ate ligands into a layer parallel to (010). O-H⋯O hydrogen bonds donated by the coordinated and uncoordinated water mol-ecules and intra-layer π-π stacking inter-actions between the pyridine rings [centroid-centroid distances = 3.551 (4) and 3.555 (4) Å] are observed. The layers inter-act with each other by inter-layer Ag⋯O(aqua) contacts [2.731 (4) Å] and π-π stacking inter-actions between the pyridine rings [centroid-centroid distances = 3.466 (3) and 3.516 (3) Å], resulting in the formation of a three-dimensional supra-molecular structure.