A process for the preparation of a tetracarboxynaphthalenediimide compound disubstituted with heteroaryl groups having general formula (I), comprising the reaction of at least one disubstituted N,N′-dialkyl-1,5,8-tetracarboxynaphthalenediimide with at least one heteroaryl compound. Said tetracarboxynaphthalenediimide compound disubstituted with heteroaryl groups can be advantageously used as monomer in the synthesis of semiconductor polymers which can be advantageously used in the construction of organic field effect transistors (OFET) or of organic thin film transistors (OTFT).