The study of binding of small molecules with supramolecular architecture comprises of one of the thriving areas of research today. In the present study, spectroscopic techniques have been used to decipher the interaction of Acridine Yellow with Cucurbit[7]uril and explore the consequence of host-guest interaction on the photophysical properties of the dye. Moreover, isothermal titration calorimetry has been used to unravel the thermodynamics of interaction. The probable causes of incongruity of the results obtained from spectroscopy and calorimetry have been rationalized. H-1 NMR study and geometry optimization of the guest molecule confirm the actual mode of host-guest interaction. (C) 2011 Elsevier B.V. All rights reserved.