Extended basis sets of gaussian functions were used to calculate near Hartree-Fock estimates of the electric dipole polarizabilities, alpha, and first hyperpolarizabilities, beta, of the inorganic benzenes B3N3H6, B3O3H3, B3P3H6 and Al3N3H6. Assuming that electron delocalization is responsible for the enhanced polarizabilities of aromatic systems, an aromaticity scale can be set up according to the trend of theoretical polarizabilities obtained in this work, i.e. alpha (B3O3H3) < alpha (B3N3H6) < alpha (C6H6), which is consistent with previous calculations of the degree of delocalization in these compounds.