The interaction of a painkiller Isoxicam, belonging to the oxicam group of nonsteroidal anti-inflammatory drugs (NSAIDs) and its copper complex with different cyclodextrins (beta-CD, gamma-CD, HP beta CD, and HP gamma CD), has been investigated in both solution and the solid state. Steady state and time-resolved fluorescence spectroscopy, fluorescence anisotropy, NMR, and FTIR spectroscopy are used. Both the drug and its copper complex form a host guest inclusion complex with all CDs. Fluorescence spectroscopy is used to determine binding constants and stoichiometries of the host-guest complex. The strongest binding is seen for gamma-CD. H-1 NMR study showed that Isoxicam penetrates into the CD cavity from the more accessible wider side. For beta- and gamma-CD, Isoxicam showed one type of binding, i.e., formation of an inclusion complex, whereas, for HP beta CD and HP gamma CD, it showed two types of binding, i.e., inclusion in the CD cavities and interaction with the outer surface of the CD molecules mainly near the hydroxy propyl group. Deeper penetration occurred into the larger diameter cavity of gamma-CD and HP gamma CD compared to beta-CD and HP beta CD. From FTIR and H-1 NMR study, it is seen that predominantly the pi-electron-rich benzene part of the drug and its complex penetrate into the host cavity.