This review article discusses the existing and potential applications of a variety of spectroscopic techniques to determine the interactions between minerals and reagents in flotation systems. To date it is found that infrared spectroscopy is the most successful and the relevant data in the literature is critically evaluated. X-ray photo-electron spectroscopy has also been successfully applied to study mineral—reagent interactions. The potential applications of other spectroscopic techniques (Raman, photo-acoustic, nuclear- and electron-spin resonance, Auger electron, secondary-ion mass spectroscopy, etc.) are also discussed in the above context. The low-surface areas of minerals in flotation systems are a major limitation to the use of some spectroscopic techniques in studying the mineral surface. The suite of reagents used in flotation systems often imposes an additional complicating feature in obtaining relevant spectroscopic data about mineral surfaces. Nevertheless, spectroscopic studies used in the above manner, will continue to give a better understanding of the flotation process.