Process for the alkylation of aromatic compounds by the reaction of the aromatic compound of interest with isopropanol, alone or mixed with propylene, wherein the reaction is carried out in the presence of a catalytic composition based on zeolite, under mixed gas-liquid phase conditions or under completely liquid phase conditions, at such temperature and pressures that the concentration of water in the reaction liquid phase is not higher than 8,000 ppm w/w, regardless of the total water content present in the reaction mixture.