The presence of organic toxic Solutes in industrial wastewater is a common environmental problem. Aniline is known to be a harmful and persistent pollutant and its presence in wastewater requires treatment before disposal. The performance of reverse osmosis to remove aniline from aqueous solutions is studied in this paper. The study has been carried out in a flat membrane test module using three thin layer composite membranes, two of polyamide, HR98PP and SEPA-MS05, and one of polyether sulphone, DESAL-3B. Recycling of both concentrate and permeate has been carried out in order to keep the feed concentration practically constant and so simulate a continuous process in a quasi-stationary state. The influence of different operational variables (pressure, feed volumetric flow rate, feed concentration and pH) on the performance of the aniline removal process is analyzed.