The fluorescence spectra of 9-anthracenecarboxylic acid (9ACA) were studied in surfactant solutions of sodium dodecyl sulfate and Triton X-100 as a function of surfactant concentration. In addition to an anthracene-like sharp fluorescence, a broad fluorescence with a peak around 470 nm appeared at 330 nm excitation above critical micellar concentrations. Only a broad fluorescence was seen at 400-nm excitation. Based on the excitation and absorption spectra. the broad fluorescence is thought to be caused by hydrogen-bonded dimers dissolved in the micelles. Intercalation of 9ACA was done for two alkylammonium-montmorillonites. The fluorescence spectra of 9ACA showed a broad peak with increase in loading levels of 9ACA in the alkylammonium-montmorillonites. The fluorescence was not similar to the excimer in a head-to-head configuration with a maximum at 510 nm observed in the crystals, but rather to the broad one in the micelles. Therefore, the hydrogen-bonded dimers are also attributed to the origin of the broad fluorescence in the interlayer spaces.