AbstractThe bulk polymerization ofN‐Vinylcarbazole (NVC) is carried out using some 3 d‐metal oxides as catalysts and the following order of reactivity is suggested for the various metal oxides studied:\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm V}_{\rm 2} {\rm O}_{\rm 5} {\rm > MnO}_{\rm 2} {\rm > TiO}_{\rm 2} {\rm > Cr}_{\rm 2} {\rm O}_{\rm 3} {\rm > NiO > ZnO > Cu}_{\rm 2} {\rm O > CuO > Co}_{\rm 3} {\rm O}_{\rm 4} {\rm andCoO} $$\end{document}the oxides of copper and cobalt being ineffective. Some kinetic studies are carried out with the NVC/MnO2system. Endorsed by the observed retardation of the rate in the presence of water and thiophene a cationic mechanism is suggested for the polymerization. The incapability of the oxides of Cu and Co to act as good catalysts is tentatively explained by supposing that they act as oxidizing rather than π‐complexing polymerization catalysts. Stirring does not show any influence on the rate of polymeri