A series of new silicon phthalocyanine monomers containing two or more hydroxyl groups has been synthesized by axial etherification of [PcSi(OH)2] with various polyfunctional alcohols, where R is a residue generated from an appropriate alcohol namely, ethylene glycol, glycerol, triethanolamine, triethylene glycol, 1,4-bis(2- hydroxyethyl)piperazine and N,N-bis(2-hydroxyethyl) isonicotinamide. All derivatives are soluble in common organic solvents such as chloroform and dioxane, and exhibit low absorptions in the visible spectral region. The dimer [RO(SiPcO)2R] and trimer [RO(SiPcO)3R] of triethanolamine have also been synthesized to investigate structure-property relationships. The above derivatives can be processes into thin polymeric films either by reacting with a diisocyanate compound or with a reactive polysiloxane. Third- order nonlinear optical properties of the above derivatives are described.