The oxidative dehydrogenation of phenol compounds, as well as polymer formation from these monomers, was studied by UV-vis and Mossbauer spectroscopy using a novel biological catalyst hematin. The mechanism of the polymerization reaction was also followed in various pH environments. Phenol radicals were formed by a two-step electron transfer reaction catalyzed by hematin in the presence of peroxide, and polymer was formed from phenol radicals by a noncatalytic reaction. This mechanism partially explains the analogous catalytic polymerization activity of horseradish peroxidase.