The present study investigated the removal of cationic textile dyes by gamma alumina nanoparticles modified with surfactant. the use of alumina nanoparticles with an anionic surfactant (sodium dodecyl sulfate) as a new and efficient adsorbent has been successfully performed to remove two dyes, basic yellow 28 and basic blue 41 from aqueous solutions of textile industrial effluents. The concentration of dyes was determined using spectroscopic method and it was found that dye removal using modified nanoparticles is performed better that unmodified nanoparticles.