Alkylation of toluene with isopropanol and methanol has been studied over alkali cation exchanged beta, Y and ZSM-5 zeolites. Over Li exchanged zeolites isopropylation takes exclusively place at the nucleus, resulting in cymenes while methylation gives xylenes and ethylbenzene, the former being the major product. Over Na, K and Cs exchanged zeolites both isopropylation and methylation occurs at the side chain, resulting in isobutylbenzene from the;former and ethylbenzene and styrene from the latter. Optimum temperatures were 648 K for isopropylation and 698 K for methylation. Formaldehyde gives ethylbenzene with an considerable amount of styrene over all the cations except the Li exchanged catalysts, while acetone gives isobutyl benzene only over NaY, KY and CsY. Over as-synthesised and Li exchanged zeolites, ethylbenzene is formed by direct dehydrocondensation of methanol and toluene while over K and Cs exchanged zeolites, ethylbenzene is formed via HCHO and styrene intermediates. Isobutyl benzene resulted by direct dehydrocondensation of isopropanol and toluene over alkali exchanged beta and ZSM-5 while over alkali exchanged Y it is formed through acetone intermediates. By comparing the data obtained by poisoning the catalyst by aniline and phenol and also the data obtained by the adsorption of NH3 and CO2 with the partial charge on the frame work oxygen, it is concluded that the side chain alkylation of toluene is a cooperative action of both acidic and basic sites.