In this work, membrane type, filtration pressure, concentration and nature of the crude oil were studied when emulsified crude oil was removed by membrane filtration methods. Interfacial interactions in the crude/water/membrane system were determined by means of interfacial tension and contact angle measurements. Diluted emulsions of Apure (33.4°API) crude oil were filtered over polysulphone and regenerated cellulose membranes and high removal of crude oil was found, with a higher efficiency of the polysulfone membrane. Nevertheless, the regenerated cellulose membrane had a higher permeate flux and better fouling resistance. Filtration done with emulsions made with Apure oil emulsions and with Lagocinco (32.7°API) oil emulsions showed that it is possible to remove 93.6% of Apure crude and 91.9% of Lagocinco crude oil. The permeate flux, fouling and crude removal are function of the interfase interaction between crude and the membrane surface.