The molecular hyperpolarizabilities gamma(-3 omega:omega,omega,omega) and gamma(-2 omega:omega,omega,0) of new soluble octasubstituted metal-free phthalocyanine 1a (R(8)PcH(2)) and metallophthalocyanines 1b,c,d (R(8)PcM, M = Cu2+, Ni2+, Co2+) have been determined by third harmonic generation (THG) and electric field induced second harmonic generation (EFISH) in chloroform solutions. Excitation wavelengths were 1.340 mu m for THG and 1.064 mu m for EFISH experiments. Both real and imaginary parts of gamma have been obtained from the concentration dependence of the harmonic intensities. While no systematic differences between the metal-free and the metallocompounds have been found in the THG experiments, a marked enhancement in the magnitude of gamma has been brought about by the metal in the EFISH measurements. Experimental THG data have been satisfactorily analyzed in terms of a four-level model including two one-photon-allowed levels (corresponding to the Q and B bands) and a one-photon forbidden level placed at around 0.5 mu m from the ground state. The enhancement of gamma observed in the metallocompounds in the EFISH experiments appeared to be related to omega resonance with additional one-photon-forbidden d-d levels associated with the metal, expected in the 1-1.3 mu m region.