Removal kinetics of phosphorus through use of basic oxygen furnace slag (BOF-slag) was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial pH, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant (k obs ) significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial pH, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage. A linear dependence of k obs on total removed phosphorus (TRP) was established with k obs =(3.51±0.11)×10 −4 ×TRP. Finally, it was suggested that the Langmuir–Rideal (L–R) or Langmuir–Hinshelwood (L–H) mechanism may be used to describe the removal process of phosphorus using BOF-slag.