Alkylation of benzene with ethanol has been done in a laboratory scale reactor with ZSM-5 diluted with silica as a catalyst. The experiments have been done at the different reaction temperatures using different catalysts in the reactor to study the change of activity and selectivity of the desired product. The feed and products were analysed by gas chromatography. Alkylation of benzene with ethanol yielded ethylbenzene as the primary product and small amount of diethylbenzene isomers. For unmodified H-type of ZSM-5 catalyst, higher conversion of benzene and the selectivity for ethylbenzene go through a maximum between 400 and 450 degreesC with a SiO2/Al2O3 ratio of around 100. The SiO2/Al2O3 ratios were varied between 34 and 331. Modified B- and Mg- types of ZSM-5 zeolites are also examined.