The current progress in molecular recognition and supramolecular chemistry of gases is presented, The structure and properties of supramolecular gas-receptor complexes is discussed. Novel chromophoric and fluorophoric sensors for detection of gases are introduced. Studies on molecules and materials for gas entrapment, separation, storage and release that involve synthetic containers, capsules and nanotubes are overviewed. It is shown that supramolecular fixation of gases leads to stable and selective chemical reagents. Gases can also be used as building blocks. Polymers and reversible, dynamic nanostructures from gases are presented. Their potential application as storing and separating materials is discussed. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007).