Since process intensification was considered one of the most promising strategies in the framework of an industrial sustainable development, membrane technology was established as powerful tool working in this direction. Among the large variety of membrane operations, membrane contactors (MCs) represent relatively new membrane-based devices that, because of their potential advantages, are gaining consideration both in industrial and scientific fields. Moreover, the integration of MCs with other traditional membrane operations makes them very competitive against conventional unit operations, and able to meet all the requirements of process intensification. An overview on the state of art and on the recent developments in MC technology is presented. Particular emphasis is placed on innovative MC applications, such as membrane emulsification, membrane crystallization and phase transfer catalysis, which are emerging as alternative options in important industrial sectors.