Bronsted acidic ionic liquids (ILs) as dual catalyst and solvent offer a potential substitute for conventional homogenous/heterogeneous catalysts and solvent for Claisen-Schmidt (CS) condensation between acetophenone and benzaldehyde to produce chalcones. The ILs showed good catalytic activities and recycle capabilities. Both the structure of cation and anion of ILs could affect the activity of ILs. The optimized reaction conditions were investigated. (C) 2007 Elsevier B.V. All rights reserved.