The importance as well as impact of application of carbon nanotube (CNT) membranes in the area of water technology development is tremendous. A substantial amount of work have been carried out with impregnation of CNTs (simply as one of the reinforcements for incorporation of better properties like antibiofouling and/or better strength, etc.) in polymer host matrix. However, the volume of work enabling CNTs as flow channels (in a membranous structure) is not significant and that is where the potential benefits of CNTs lie. Moreover, from impressive works carried out in this direction, it is quite obvious that still significant challenges have to be addressed to align the CNTs, to reinforce it in a suitable host matrix without disturbing the alignment and inhibiting the agglomeration (adoption of suitable nanocomposite fabrication route), to open the tips preferentially and to scale up favorably. It is believed that the innovative attributes put forth by CNTs and the application areas identified with CNTs are getting matured, while the area of development of CNT (based) membranes is far from being matured and it still needs to be looked into in the light of involvement of materials as well as process challenges. © 2012 Elsevier Ltd. All rights reserved.