The Baeyer-Villiger oxidation of some aldehydes and ketones has been revised by using the electrophilicity as a descriptor of reactivity. The global electrophilicity index evaluated at the ground state of a series of aromatic aldehydes and ketones shows a linear relationship with the sigma(p) Hammett substituent constants. The theoretical scale correctly accounts for the electrophilic activation/deactivation effects promoted by electron withdrawing and electron releasing substituents in these molecules. (C) 2008 Elsevier B. V. All rights reserved.