Abstract: A process for preparing terylene-3,4:11,12-tetracarboximides I where the variables are each defined as follows: R, R? are each independently hydrogen; if desired substituted alkyl or cycloalkyl; R1 is hydrogen or alkyl; R2 is hydrogen; alkyl; if desired substituted aryl or hetaryl, by reacting a perylene-3,4-dicarboximide II in the presence of a base-stable, high-boiling organic solvent and of an alkali metal or alkaline earth metal base, with a naphthalene-1,8-dicarboximide III in which X is hydrogen, bromine or chlorine.