We report ab initio calculations of the Kirkwood-Frohlich g-factor for methanol. Our results give evidence in favour of using for the high frequency permittivity epsilon(infinity), in the Frohlich formula for the dielectric constant, the value corresponding to the plateau after the first relaxation in the curve epsilon(') vs. frequency (epsilon(') real part of the complex permittivity) instead of the commonly used value 1.1n(2) (n = refraction index). (C) 2004 Elsevier B.V. All rights reserved.