A new generation of chemically modified, FILMTEC* thin-film composite, aromatic polyamide membrane elements has been introduced that exhibits reduced rates for bacterial adhesion, longer induction periods before biofilm start developing, and extended operating times between chemical cleanings. When these biofouling-resistant (FR) elements are coupled with the optimized use of selected biocides to prevent biofilm growth, a significant reduction in chemical cleaning frequency is achieved. This paper reviews biofouling in membrane systems and describes the development of the FR elements through full-scale field trials over about 3 years, focusing in the improvement achieved in mitigating the negative effects of biofouling on the performance of reverse osmosis plants. Some economic guidelines are given to estimate the potential value of FR technology.