In present research a powerful adsorbent was fabricated and employed for removal of anionic reactive dye, Reactive Black 5 (RB5) from aqueous solutions. Polyethylenimine (PEI)-polyvinyl chloride (PVC) composite fiber was prepared by spinning PEI-PVC blend into the mixture of water and methanol. To evaluate the dye sorption performance of PEI-PVC fiber, various parameters that included the effect of pH, dye concentration, contact time, and salt concentration in a batch process were studied. The optimal pH for hydrolyzed RB5 adsorption was observed in the range of pH 2.0-5.3. The sorption kinetic data were better fitted to the pseudo-second-order kinetic model compared with the pseudo-first-order kinetic model. Adsorption isotherm experiments were fitted to the Langmuir model and the maximum uptake of the PEI-PVC fiber was estimated. At a low initial dye concentration, the effect of salt concentration was negligible. However, RB5 uptake was significantly decreased with increasing salt concentration at a high initial dye concentration. By using 0.01 M NaOH, RB5 was easily desorbed from the dye-loaded PEI-PVC fiber. These findings suggested that PEI-PVC fiber can be successfully used as an adsorbent for removal of anionic reactive dyes from aqueous effluents. (C) 2015 Elsevier B.V. All rights reserved.