A method is disclosed for preparing symmetrical azines of the formulas ##EQU1## and unsymmetrical azines of the formulas ##EQU2## and mixtures of azines (I), (II) and (IV) and (I), (III) and (V), wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each is a hydrogen atom, a straight chain alkyl radical of from 1 to 12 carbon atoms, a branched chain alkyl radical or unsubstituted or alkyl substituted cycloalkyl radical of from 3 to 12 carbon atoms, a hydrocarbon radical of from 6 to 12 carbon atoms containing a benzene ring; further provided that R.sup.1 and R.sup.2 can be the same or different radicals, R.sup.3 is a radical different from R.sup.1 and R.sup.2 and R.sup.3 and R.sup.4 are radicals different from each other and each are different from R.sup.1 and R.sup.2 ; or R.sup.1 and R.sup.2 or R.sup.1 and R.sup.3 or R.sup.3 and R.sup.4 bonded to the same carbon atom together form an unsubstituted or aliphatic substituted alkylene radical of from 3 to 11 carbon atoms, each of the aforesaid radicals being unsubstituted or substituted with one or more radicals which are stable in the medium in which the azines are produced.The method comprises reacting ammonia and a carbonyl compound of the formula ##EQU3## alone or together with a different carbonyl compound ##EQU4## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each have the same meaning defined above with at least one diacyl peroxide (acyl peroxide) which are compounds having one or several groups of the structure ##EQU5## and recovering the azine or mixture of azines from the reaction medium.