A nonlinear mapping (NLM) analysis was performed bn a set of 166 aromatic substituents described by six variables encoding hydrophobic (pi), steric (MR), and electronic effects (HBA, HBD, F, and R). NLM allowed to easily summarize the main information contained in the original data table. By means of collections of graphs, it was possible to relate the structure of the substituents to their pi, MR, HBA, HBD, F, and R values. The proposed approach provides a useful and easy tool for the selection of test series and for deriving structure-activity relationships.