The utilization of treated basic oxygen furnace slag (BOF slag) was successfully carried out to remove three synthetic textile dyes (Reactive Blue 19 (111319), Reactive Black 5 (RB5) and Reactive Red 120 (RR120)) by adsorption from aqueous solutions. Batch studies were carried out to address various experimental parameters such as pH, contact time, temperature and ionic strength. In the batch system, the maximum dye uptake on acid treated BOF slag adsorbent was observed at pH 2.0, and the maximum RB5, RB19 and RR120 uptake capacities (at 500 mg l(-1) dye concentration) were 76, 60 and 55 mg g(-1). The Langmuir and Redlich-Peterson models were able to describe the adsorption equilibrium. The first-order, Elovich and intra-particle diffusion models were used to describe kinetic process of dyes adsorption and adsorption kinetic process is following the first-order kinetic model. (C) 2008 Elsevier B.V. All rights reserved.