In the crystal structure of the polymeric title compound, {[Pb(C(9)H(9)O(2))(2)(C(6)H(6)N(2)O)]·H(2)O}(n), the six-coordinate Pb(II) ion is chelated by two 4-ethyl-benzoate (PEB) anions and is bridged by two nicotinamide (NA) ligands, forming a polymeric chain running along the b axis. The carboxyl-ate groups of the PEB ions are twisted away from the attached benzene rings by 4.0 (6) and 13.3 (5)°. The two benzene rings of the PEB ions bonded to the same metal ion are oriented at a dihedral angle of 87.4 (3)°. In the polymeric chain, the NA ligand is linked to one of the carboxyl-ate groups via N-H⋯O hydrogen bonding. In the crystal, adjacent polymeric chains inter-act via N-H⋯O and weak C-H⋯O hydrogen bonds; and the lattice water mol-ecule links with the polymeric chains via N-H⋯O and O-H⋯O hydrogen bonding. π-π stacking between the benzene and the pyridine rings [centroid-centroid distance = 3.805 (5) Å] and weak C-H⋯π inter-actions are also observed in the crystal structure.