Acylated imidazoles of the formula ##STR1## where R.sup.1 and R.sup.3 are each H, alkyl of from 1 to 12 carbon atoms, alkenyl of from 1 to 12 carbon atoms, aryl, aralkyl or alkylaryl, R.sup.4 is H, alkyl of from 1 to 12 carbon atoms, alkenyl of from 1 to 12 carbon atoms, aryl, aralkyl or alkylaryl, and R.sup.5 is alkyl of from 1 to 12 carbon atoms, alkenyl of from 1 to 12 carbon atoms, aryl, aralkyl, alkylaryl or carboxyl, are prepared by reacting imidazoles of the formula ##STR2## where R.sup.1, R.sup.2 and R.sup.3 are each alkyl of from 1 to 12 carbon atoms, alkenyl of from 1 to 12 carbon atoms, aryl, aralkyl or alkylaryl, at least one of the radicals R.sup.1, R.sup.2 and R.sup.3 being hydrogen, and R.sup.4 is H, alkyl of from 1 to 12 carbon atoms, alkenyl of from 1 to 12 carbon atoms, aryl, aralkyl or alkylaryl, with widely used acylating agents of the formula ##STR3## where R.sup.5 is as defined above and Y is halide, alkoxy, acyloxy or hydroxyl, in the presence of acidic metal oxides and/or phosphates, preferably in the gas phase.