In a membrane contactor the membrane separation is completely integrated with a conventional phase contacting operation like extraction or absorption. In this way the benefits of both technologies can be fully exploited. The membrane contactor technology is a new technology. The first full scale membrane contactor installations that have been installed in industry are running successfully for some years now. Industrial applications of membrane contactors, including aromatics recovery from a process water, selective removal of heavy metals from a galvanic process bath and ammonia product recovery from an off gas stream, are discussed. Membrane contactors are of interest for the chemical, petrochemical, pharmaceutical and galvanic industry for both water and gas treatment as end of pipe technology but also for product recovery and as integrated process solution. New applications under development-CO2 membrane gas absorption and pertraction for produced water treatment-are discussed technically and economically to show the wide scope of the technology.