Liquid-phase transalkylation of phenol with cumene was studied over various zeolites. Among the evaluated catalysts, ZSM-5 zeolites showed higher activities (ca. 50% phenol conversion) and usage efficiencies of isopropyl groups (ca. 80%) at 200 degrees C and 1.5 MPa. The higher catalytic performances of ZSM-5 zeolites are closely related to their channel structure and moderate cumene uptake capacities. It has been shown that the activities are related to the strong acidity of ZSM-5 zeolites. The passivation of external acid sites on ZSM-5 zeolite enhances the selectivity for para-isopropylphenol.