IN THE present study, polyaniline (PANI), chemically synthesized …..using ammonium peroxydisulfate [APS] and by catalyzed hydrogen peroxide (H₂O₂), was evaluated as adsorbents for reactive (blue 19) dye. Experiments were conducted in batch mode where some parameters affecting the adsorption capacity such as contact time and concentration of dye have been investigated. An atomic absorption spectroscopy method was used for the measurement of dye contents. Adsorption equilibrium was achieved within 60 min and the adsorption capacity (q_e) was 350 mg /gm (PANI) under the optimal conditions. Adsorption equilibrium studies were carried out and showed that adsorption follows the Freundlich model. The adsorption kinetics was best described by the pseudo-second-order model. The results indicated that PANI, synthesized by catalyzed hydrogen peroxide (H₂O₂) can be used as a novel effective adsorbent material for the removal of the tested reactive dye with higher adsorption capacity than PANI prepared by APS.