Directed metallation using organolithium bases is one of the best ways of regiospecifically elaborating aromatic systems and their substituents. For benzenoid arenes, deprotonation occurs at the ortho, lateral or peri positions. The reasons for each type of reaction will be considered in the context of the propensities of different directing groups for complex formation with the incoming organolithium base, acidification of the reactive site(s) and post‐reaction stabilisation of the metal ion(s). Discussion will concentrate on structural investigations, for the most part by single‐crystal X‐ray diffraction and/or by multinuclear NMR spectroscopy. Theoretical studies will also be incorporated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)