In the title Zn(II) complex, [Zn(C(8)H(8)NO(2))(2)(C(6)H(6)N(2)O)(2)]·H(2)O, the Zn atom is coordinated by two 4-methyl-amino-benzoate (MAB) and two isonicotinamide (INA) ligands in a distorted trigonal-bipyramidal geometry; one of the MAB ions acts as a bidentate ligand while the other MAB and the two INA are monodentate ligands. The dihedral angles between the carboxyl groups and the adjacent benzene rings are 8.52 (22) and 5.10 (14)°. In the crystal, inter-molecular O-H⋯O and N-H⋯O hydrogen bonding links the mol-ecules into a supra-molecular structure. Weak inter-molecular C-H⋯O inter-actions are also present.