The excess content of phosphate in laundry wastewater can cause eutrophication. Ion exchange is a method that has been widely used to remove pollutants in wastewater. The study of ion exchange equilibrium is generally carried out by means of adsorption isotherms modelling. The use of adsorption isotherms to model ion exchange systems involves that it is interpreted as a sorption process. The performance of an adsorbent can be studied by adsorption isotherm data which can be obtained by the experimental test in the laboratory. Modeling of adsorption isotherm data is a fundamental way to predict and compare adsorption performance, which is needed for the optimization of the adsorption mechanism pathways, the expression of the adsorbent capacity, and effective design of the adsorption system. This research applied three isotherm models namely Langmuir, Freundlich, and Dubinin-Radushkevich to determine and compare the isotherm models that suits best to remove phosphate on laundry waste using Lewatit MonoPlus MP 500 OH anion resin. The best fitted for phosphate removal using Lewatit MonoPlus MP 500 OH was using the Freundlich isotherm model with 5 ml/minute for the best flow rate and 166 cm 3 anion resin volume.