The use of dynamic membranes formed in situ by deposition of a colloidal suspension on a porous support as a pretreatment of membranes is an attractive method to reducing irreversible membrane fouling. A polyethersulfone, PVDF, membrane with a neutral load, hydrophilic character and a cut-off of 30,000 Dalton was studied after treatment with hydrophilic polymers, such as polyetylenoglycol and polyvinyl alcohol. The selectivity and permeability of the membrane without treatment and of the dynamic membranes formed with hydrophilic polymers were measured with a solution of a reactive dye, Black Remazol B, at different pH values. Simultaneously, fouling of the membrane was controlled. It was observed that for identical conditions permeate flux is higher with membranes treated with solutions of hydrophilic polymer and irreversible fouling decreased with the treatment of the membranes.