The title compound, [Mn(C(16)H(14)N(2)O(2))(C(7)H(4)NO(4))(H(2)O)], is a Jahn-Teller-distorted manganese(III) monomer with an octa-hedral geometry. The tetra-dentate Schiff base accommodates the Mn(III) ion at the centre of a nearly planar square. The axial positions are occupied by a monodentate carboxyl-ate group and a water mol-ecule. Adjacent monomers inter-act through hydrogen bonding between the noncoordinated C=O group of the carboxyl-ate and the coordinated water mol-ecule to produce chains extending parallel to the b axis.