Polymerization of biphenyl, terphenyl and quaterphenyl has been studied by the electrochemical quartz crystal microbalance technique and the influence of the concentration of starting material, temperature and polymerization potential on the polymerization reactions investigated. The results of a mechanistic analysis clearly show that the polymerization at low potentials is dominated by a one-step dimerization reaction, producing a film material consisting of short chains. When biphenyl is used as starting material, the yield of film layer is low due to the high solubility of the short phenylene oligomer intermediates. With higher oligomers as starting material, the yield is higher, as the intermediates are less soluble. The yield of film material was lower when the concentration of biphenyl was increased or when a high polymerization potential was applied. By lowering the temperature during polymerization of biphenyl, the solubility of the oligomers was reduced and an efficient deposition process was observed.