Diffusional-viscosimetric analysis of liquid crystal metallocomplexes of holmium and dysprosium with 4-alkoxy-N-alkyl-2-hydroxybenzaldiimines in the protonated (zwitterionic) form and various counterions demonstrated that the complexes of the lanthanides with perfluoroalkylsulfate anions have hydrodynamic sizes half those of the complexes with nitrate anions, with the type of lanthanide having virtually no effect on the size of the complex. The results correlate with the geometric size of the ligand and the parameters of the mesophase and crystal lattice of the complex.