Alkylation of benzene with propylene or isopropanol (IPA) results in the formation of isopropyl benzene (cumene) which is used almost extensively for the production of phenol and acetone using different catalysts. However, use of propylene, as alkylating agent at very high temperatures leads to coke formation which results in deactivation. In this paper, we report more active and selective catalyst-20% (w/w) Cs2.5H0.5PW12O40/K-10 for the vapour phase isopropylation of benzene to cumene using isopropanol at much milder conditions vis-a-vis other catalysts reported so far. A pseudo-first order kinetic equation is used to fit the experimental results and evaluate the Arrhenius parameters. (C) 2004 Elsevier B.V. All rights reserved.