Abstract: The present invention provides new 1,4-distyryl-benzene derivatives corresponding to the formula ##SPC1##Wherein R represents alkyl with 1 to 8 carbon atoms which is optionally substituted by non-chromophoric radicals, phenyl which is optionally substituted by non-chromophoric radicals, alkenyl with 2 to 4 carbon atoms or cycloalkyl with 5 or 6 carbon atoms, X represents hydrogen, chlorine, or alkyl with 1 to 4 carbon atoms, Y and Y' each independently represents hydrogen, chlorine, methyl, methoxy or ethoxy, and n is 1 or 2. The new compounds are valuable optical brighteners for organic materials, especially for polyesters.