In this paper, the effect of various operating parameters and conditions for emulsion formulation on flux and rejection was investigated in the ultrafiltration (UF) of W/O/W double emulsions. It was found that the viscosity of W/O/W double emulsions played an important role in UF flux. The membrane fouling behavior was observed and analyzed using the concept of a modified fouling index. Under the conditions studied, the total organic content rejection was higher than 0.95 equivalent to 100 to 400 ppm and UF flux normally reached about 60% of pure water flux. In addition, the fouled cellulosic membranes could be easily cleaned. The present study demonstrated that the application of UF to the separation of W/O emulsions from external phase would be incentive in liquid surfactant membrane processes.