The Friedel-Crafts alkylations of benzene in pyridinium-based ionic liquids (ILs) were investigated. The effects of catalyst-IL composition, reactant composition, quantity of catalyst and reaction temperature on this reaction were studied. The reactions were found to proceed under mild conditions with conversion; a simple product isolation procedure was achieved. The ILs rendered this reaction green characteristics. The ILs could also be recycled and reused as opposed to traditional solvent-catalyst systems. (c) 2004 Elsevier B.V. All rights reserved.