Cotton-Mouton constants C-m of nematogenic oligomers of the oxybenzoate series have been determined in solution. The experimental values of C-m were compared with the Cotton-Mouton constant calculated from group additivity schemes : For the tenser of the diamagnetic susceptibility, the scheme of Flygare (Chem. Rev. 1974, 74, 653) was used, and for the polarizability tenser group, contributions deduced previously from depolarized Rayleigh scattering (DRS; J. Phys. Chem. 1990, 94, 3215) were employed. Good agreement of measured and calculated C-m values is found. The influence of the local field correction used for the evaluation of both the DRS and the Cotton-Mouton constant is discussed.