An information-theoretical analysis of the SN2 exchange reaction for CH3Cl + F− is performed in both position and momentum spaces by means of the following functionals of the one-particle density: Shannon entropy (S), disequilibrium (D), and Fisher information (I). We have shown that the information-theoretical characterization of the chemical course of the reaction is in complete agreement with its phenomenological behavior in the passage from reactants to products. These kinds of analyses permit to reveal all the concomitant physical processes involved in the reaction: charge transferring, bond breaking, electrostatic equalization, bond forming, and electrostatic repulsion. It is worth emphasizing that information theory concepts, such as localization, order, and uniformity, offers a unique advantage as a complementary reactivity theory to provide a full description of chemical reactions, revealing chemical aspects of reactions which are not present in the energy-based interpretative approach. © 2013 Wiley Periodicals, Inc.