In the present work, we studied the role of an anionic surfactant, sodium dodecyl sulfate, and a cationic surfactant, dodecyltrimethylammonium chloride, in the sorption of 4,4'-distyrylbiphenyl sodium sulfonate (Tinopal CBS) onto modified cellulose fibers. Fluorescence spectroscopy was used to quantify the amount of sorbed Tinopal CBS on the fiber surface. Differences in the spectral properties and the efficiency of sorption of the whitener/surfactant/fiber system are explained in terms of electrostatic interactions. Our results also show that the sorption efficiency is greater for solutions containing cationic surfactants only below the critical micelle concentration, while anionic surfactants show a smooth influence on the sorption process.