The interactions between differently structured surfactant molecules at the solid/liquid and air/liquid interfaces and their effectiveness for efficient flotation were recognised during the 1950＇s, while no sincere effort has been made to understand the mixed collector systems on flotation performance. In recent years, interest has increased for the use of mixtures of anionic/nonionic and anionic/cationic collectors for enhancing the selectivity and recovery. This paper reviews the flotation studies reported on the use of various collector combinations and discusses the behaviour of mixed collectors at the mineral/water interface.