The ring opening metathesis polymerization (ROMP) of norbornene dicarboximide derivatives 3(a-c) bearing halo-substituted phenyl groups was carried out with well-defined organometallic catalyst (PCy3)(2)(Cl)(2)Ru=CHPh. This catalyst is highly active for the polymerization of norbornene dicarboximide derivatives. Exo-N-4-chlorophenyl-norbornene-5,6-dicarboximide (ClPhNDI, 3a), exo-N-4-bromophenyl-norbornene-5,6-dicarboximide (BrPhNDI, 3b), exo-N-4-iodophenyl-norbornene-5,6-dicarboximide (IPhNDI, 3c) monomers gave high molecular weight thermoplastic polymers in high yields (77-96%). All of the prepared polymers were soluble in common organic solvents at room temperature and gave similar IR and NMR spectra. Their glass transition temperatures were detected at temperatures over 187 degrees C. The surface properties of ROMP polymers were investigated by SEM. (C) 2010 Elsevier B.V. All rights reserved.