Basic oxygen furnace slag (BOF slag) is a final waste in the steel making process, which contains 12.5 and 4.5 wt% of FeO and Fe2O3, respectively. The abundant iron-containing property of BOF slag makes it a possible catalyst for Fenton's reactions. This study evaluated the performance of H2O2 with BOF slag denoted as H2O2/BOF slag process to degrade 2-naphthalenesulfonate (2-NS). The concentration of total organic carbon (TOC) was chosen as a mineralization index of the degradation of 2-NS by the H2O2/BOF slag process. The experimental results revealed that the adequate pH values for better mineralization of 2-NS were found to be below 3. An optimum mineralization efficiency of 2-NS was evaluated as the BOF slag loading and the initial concentration of H2O2 were 15 g/L and 700 mg/L, respectively.