Different types of microstructures and their applicationswith respect to the synthesis and the use of ionic liquids are presented. Microstructured reactors are suitable for reactions with fast intrinsic kinetics, requiring high mass and heat transfer performances. Chemical synthesis can be performed safely underoperatingcondition (e.g. hightemperature, pressure, etc.) difficult too btain in traditional reactors. The examples presented clearly indicate thatmicrostructuredreactorsoffersuperior performance for the synthesis of ionic liquids in comparisontoconventional equipment. For the use of ionic liquids as reaction media, existing ionic liquids shows ome limitations due to their higher viscosity compared to conventional solvents. Therefore, future research shouldbefocused on the development of low viscosity ionic liquids. The approachestouseionicliquidsinmicrostructured reactors and in combination with microstructured supports for catalytic reactions show many advantages inviewofhighproduct selectivity and yield. The use of supported ionic liquids on microstructured materials seems to be particularly promising for gas phase as well asfor g as/liquid reactions. (C) 2010 ElsevierLtd. All rights reserved.