Oxidation of microparticles of lutetium (bis-tert-butylphthalocyaninato) complex immobilized on the surface of paraffin-impregnated graphite electrode and immersed into an aqueous electrolyte was investigated by cyclic voltammetry and square wave voltammetry. The electrode reaction exhibits the typical features of insertion electrochemistry where the anions of the aqueous electrolyte are transferred into the solid phase upon oxidation of the redox centers there in. The reaction is quasi-reversible and influenced by the ohmic resistance of the compound. The formal potentials of the electrode reaction involving the transfer of perchlorate, nitrate, and chloride ions follow the same order as the Gibbs energies of ion transfer in the systems water–nitrobenzenene and water–octanol. Bromide and thiocyanate ions are not intercalated.