In this critical review, the use of iron(III) chloride in oxidative C-C couplings of arenes and related unsaturated compounds is presented and reviewed. The approach allows highly selective dimerisations of phenol derivatives, naphthols, and heterocyclic compounds. Sequential couplings give access to structurally well-defined oligo- and polymers. Iron(III) chloride is commercially available and inexpensive. Being a mild oxidising agent it has been applied in numerous reactions leading to new carbon-carbon-bonds in complex molecular arrays (107 references).