This study addresses the efficiency of nanofiltration to remove different pesticides and hormones from different real water sources (surface water and groundwater) and the effect of the ionic composition of different water sources on the rejection of the target micropollutants. Ultrafiltration was performed prior to the nanofiltration process to remove particulate and large colloidal organic matter, that interfere in the rejection of micropollutants during nanofiltration, without affecting the concentration of ionic species and natural organic matter present in the water. The other aim of this study was to understand the role of adsorption on the rejection of the solutes selected, which was tested by conducting membrane pre-adsorption experiments using these micropollutants under static and dynamic conditions. High percent rejections (67.4-99.9%) were obtained for the pesticides and hormones, often independently of the water composition. Size exclusion and hydrophobic interactions were found to highly influence the rejections obtained. The lower rejections (57.5-83.5%) obtained for pentachlorophenol could be explained by its increased solubility at the waters' pH. The overall nanofiltration efficiency to remove the selected compounds was not found to be considerably affected by the pre-adsorption of the compounds on the membrane under static and dynamic conditions, except for 17 alpha-ethinylestradiol, estrone, and estriol in surface water. (C) 2012 Elsevier B.V. All rights reserved.