The reverse osmosis (RO) technology offers a solution for the shortage of pristine water resources worldwide, through its capacity on treating all water kinds such as seawater, wastewater, ground water and surface water. The main concern in using RO technology for water treatment is fouling problems, and in particular biofouling. Biofouling negatively affects the quality of RO product and renders RO a costly technology for water treatment. The key solution to reduce the risk of biofouling in RO system lies in understanding the process of biofouling formation, choosing an adequate biofilm monitoring technique and applying effective biofouling control treatment for the RO membrane system. In this paper, the mechanisms of microbial adhesion to RO membrane are illustrated along with the key factors that influence the microbial adhesion process. In addition to that, the common strategies for biofilm monitoring in water flow systems are reviewed with highlighting applications, advantages and disadvantages of each strategy. The common biofouling control methods for reducing the formation of biofouling in the RO system are also presented in this paper. The application of the environmentally friendly physical disinfection techniques for biofouling control in the RO membrane system is suggested in this paper. (c) 2012 Elsevier B.V. All rights reserved.