The optimized application of micellar-enhanced ultrafiltration (MEUF) in industrial scale requires the ability to develop simulation models. The more conventional approach for the description of relationships between operation conditions like, for example, surfactant concentration and separation performance and fouling, centers on the evaluation of overall resistance and time-independent relationships between concentrations before and after the membrane. In this paper, a novel approach is presented. It is based in the evaluation of relationships between averaged resistance and permeation fluxes, and a molar ratio pollutant/surfactant to predict the efficiency of the separation. The evolution of the additional resistance to permeation generated by the deposition of surfactant on the membrane is described as a sequence of. a maximum initial resistance due to gelification; a decrease in the resistance, apparently connected with the deformation of the surfactant gel by the permeating flux; and an aging effect. It is observed that different pollutants have different effects on the initial resistance and its evolution. In the case of phenol, higher concentration causes an increase of the initial resistance. It does not seem to have an effect on the aging rate.