The influence of various interface forces on membrane fouling during reverse-osmosis (RO) filtration of organic solutions is investigated. Some monoaromatic compounds are used as model foulants. Isothermal data demonstrate that the adsorption of aromatic compounds on the membrane surface fits the Freundlich model better than the Langmuir model. Kinetics data are better correlated with the pseudo-second-order model than the pseudo-first-order one. The affinity of monoaromatic compounds to the RO membrane is evaluated. Statistical analysis of results indicates that the initial fouling rate is dominated by the electrostatic attraction and the hydrophobic force while irreversible fouling is mainly controlled by the formation of a hydrogen bond between the membrane surface and organic compounds.