A blue-light-emitting electroluminescent polymer was prepared by the ring-opening metathesis polymerization (ROMP) method from a norbornene monomer (NBTPV-C5) that contains a phenylenevinylene oligomer unit as a side chain. A 50mer of NBTPV-C5 (M(w)/M(n), 1.10) was prepared in THF in 95% yield by employing Mo(NAr)(CHCMe(2)Ph)(O-t-Bu)(2) as the initiator. Electroluminescent devices were made with single layers of polyNBTPV-C5 with ITO as the anode and Ca as the cathode, both by itself and in blends containing the electron transport material, biphenyl-tert-butylphenyloxadiazole. Two layer devices using PPV as a hole transport layer also were prepared. Electroluminescent quantum yields of up to 0.55% have been obtained.