Two copper(II)-gadolinium(III) metal complexes of formula (CuGdLX3)-Gd-II-L-III are reported. H2L stands for the Schiff base ligand obtained by condensation of 3,4-dimethoxysalicylaldehyde with ethylenediamine (complex 1) or 1 R,2R-(+)1,2-diphenylethylenediamine (complex 2). While 1 reveals a centrosymmetric crystal structure, 2 crystallizes in the noncentrosymmetric P2(1)2(1)2(1) space group and exhibits an efficiency 0.3 time that of urea in second harmonic generation. Due to a trend for dissociation in solution, the molecular hyperpolarizabilities (beta) cannot be determined experimentally for 1 and 2. Nevertheless, the electric field induced second harmonic (EFISH) technique, in connection with spectroscopic data and a ZINDO semiempirical approach, leads to a beta value of -6.5 x 10(-30) cm(5) esu(-1), for the related (CuL)-L-II monomers, as an indicative range of magnitude in all these Schiff base complexes. In addition, 1 and 2 exhibit a ferromagnetic coupling in solid state with (H) over cap = 3.3 and 1.3 cm(-1), respectively (J being the parameter of the exchange Hamiltonian = -JS(Cu)(.)S(Gd)).