Arsenic removal from drinking water is a major problem in many parts of the world. Acute and chronic arsenic exposure through drinking water has been reported in many countries, especially Argentina, Bangladesh, India, Mexico, Mongolia, Thailand and Taiwan, where a large proportion of ground water is contaminated with arsenic at levels from 100 to over 2000 mu m/L. In this work. we have investigated the arsenic removal by the membrane-based nanofiltration (NF) technique. The results of this study demonstrate that arsenate ions removal by NF with a high rejection of 99.80% along with total dissolved solids (TDS) and other contaminates were achieved, Significant flux was retained at the end of each NF experiment with operation time of 180 min, which suggests that membranes were not affected by the fouling phenomenon during the process run. The feasibility of membranes for treating drinking water by varying feed pressure, pH and feed concentration was tested on the separation performance of the thin film composite NF membranes. (C) 2009 Elsevier B.V. All rights reserved.