Micellar enhanced ultrafiltration (MEUF) was used to remove cationic dye from aqueous solution. Sodium dodecylsulfate (SDS) and Safranin T (ST) (molecular weight 350.85) have taken as anionic surfactant and cationic dye, respectively. Regenerated cellulose membrane of molecular weight cut-off 10 kDa was used in a cross-flow ultrafiltration unit. The effects of operating conditions, i.e., feed dye concentration, feed surfactant concentration, pH and ionic strength on the permeate flux and observed retention of dye are investigated. The ultrafiltration experiments showed that anionic surfactant SDS allowed retention of Safranin T in the order of 99% in the whole range of dye and surfactant concentrations considered. High retention was also obtained at pH range from 2 to 11. Permeate flux decreases when surfactant concentration or ionic strength increases.