This review describes the synthesis of 1,3-tetrachalcogenafulvalenes and 1,2-tretrathiafulvalenes, the chemical transformation of substituents, reactions of the ring system, and the synthesis of polymers with 1,3-tetrathiafulvalene units in the backbone and in the side chain. 1,2-And 1,3-tetrachalcogenafulvalenes synthesized until now and selected properties (melting point, u.v.-vis. absorption data and oxidation potential) are recorded in appropriate tables. The literature until the end of 1985 is taken into account.