Nanosized gamma-Al2O3 catalyst was prepared by the alkoxide sol-gel method and characterized by XRD and TEM. The porous nature of the catalyst was studied by nitrogen adsorption-desorption isotherms. Acidity of the synthesised material was analyzed by pyridine-adsorbed FT-IR spectroscopy. The gas phase alkylation of isomeric methylphenols (cresols) with isopropyl alcohol over sol-gel prepared alumina catalyst was studied. The reactions were carried out in a continuous process at the atmospheric pressure with dependence on temperature, starting at 210 degreesC up to the point when the amount of alkylated cresols dropped due to decomposition. Both, O- and C-alkylated products were obtained at lower temperatures, while at higher temperatures ortho-isopropylated derivatives of isomeric cresols were the main products. According to the present method isopropylated cresols can be efficiently obtained with selectivity higher than 90%. (C) 2004 Elsevier B.V. All rights reserved.