A process for the alkylation of aromatic hydrocarbons with alkylating agents having from one to five, and preferably three to five, carbon atoms. The reactants are brought into contact, preferably in the liquid phase, in the presence of a crystalline zeolite catalyst characterized by a silica to alumina ratio of at least 12 and a constraint index within the approximate range of 1-12. The reaction is conducted at 100.degree. C. to 300.degree. C. and a pressure of from about 10.sup.5 N/m.sup.2 to about 2.times.10.sup.7 N/m.sup.2.