In this work, the removal of urea from industrial wastewater by thermal hydrolysis was studied. The performance of the hydrolyzer was investigated using an equilibrium-based model. This model incorporates two sets of important equilibrium reactions and takes into account the effects of liquid nonideality on the reaction equilibria. It provides outlet temperature, concentration, and flow rate of different components in the reactor. The predicted data of the model were consistent with the plant data, indicating the validity of the model. The impact of different parameters on the performance of urea hydrolyzer was examined. The result of this work showed that an increase in inlet wastewater temperature and steam flow rate would improve the urea removal efficiency.