The quadratic hyperpolarizabilities of three axially substituted Indium phthalocyanines (Tn-Pcs) (1-3) in chloroform solution have been measured by the EFISH technique at lambda = 1064 nm. A maximum value of 37.4 x 10(-30) esu has been obtained for the trifluoromethylphenyl-substituted compound 3. The data have been analyzed with a two-level model corresponding to the Q-band and so the nonresonant values for the quadratic hyperpolarizability, beta(z)(0), have been determined by taking into account the electronic contribution to gamma(EFISH). The three components chi(15)((2)), chi(31)((2)), and chi(33)((2)) and of the susceptibility tensor have also been obtained for spin-coated films containing the three compounds dissolved in PMMA. Susceptibilities reach the highest values, chi(15)((2)) = 3.3 x 10(-10) esu, chi(31)((2)) = 3.9 x 10(-10) esu, and chi(33)((2)) = 13.1 x 10(-10) esu, for compound 3. Kleinman symmetry is approximately obeyed particularly for the Cl-substituted compound 1.