Starting with commercially available methyl 2,5-dichlorobenzoate, poly(p-phenylene) with a highly regular structure, which showed high conductivity after SbF5-doping, has been prepared by the decarboxylation of poly(2-carboxyphenylene-1,4-diyl); it is soluble in pyridine, quinoline and aqueous sodium hydroxide solution and has a degree of polymerization around 100.