Electro-optical properties of optically active mesogenic n-alkyl sulfinates are reported. Two homologous series have been considered, and the properties have been analyzed as a function of the length of aliphatic terminal chains. It is shown that the anisotropic distribution of the transverse dipole moments of the molecules, f, decreases strongly (by about 50%) with increasing chain length for a given tilt angle; this behavior is attributed to large orientational fluctuations. It is shown also that f increases slightly with increasing chain length al a given distance from the transition temperature between the C* and A phases; this is attributed Eu a better defined building of different smectic sublayers. These two antagonistic effects, together with the dilution effect, act simultaneously in order to keep the spontaneous polarization practically independent of the aliphatic chain length, whereas the tilt angle of the molecules within the smectic C* layers is quite dependent of aliphatic chain length, at a given distance from the transition temperature.