The article deals with synthesis, characterization, and polymerization of 5norbornene-2,3-dicarboximide end-capped resins (bisnadimides) based on 4,4diaminodiphenylether, 1,4/1,3-bis(4 -aminophenoxy) benzene, 2,2 -bis[4-(4-aminophenoxy)phenyl]propane, and bis[4-(4 -aminophenoxy)phenyl]sulphone. Both exo and endo bisnadimides were prepared by reacting the aromatic diamines with exo or endo nadic anhydride in glacial acetic acid at 120ЊC. The exo or endo bisnadimides could be distinguished on the basis of differences observed in IR or 1 H-NMR spectra. Both thermal (in solid state) and metathetical polymerization (using WCl 6 /tetramethyltin catalyst and chlorobenzene solvent) of bisnadimides was carried out. Only exo bisnadimides could be polymerized using metathesis reaction whereas thermal polymerization of both endo and exo bisnadimide could be successfully carried out at 300ЊC in static air atmosphere. The polymers were highly crosslinked and insoluble in common organic solvents. The polymers obtained by metathesis polymerization were light brown in color whereas those obtained by thermal polymerization were dark brown in color. Thermal stability of the thermally polymerized exo or endo bisnadimides was comparable. These polymers were stable up to 400ЊC and decomposed in a single step above this temperature. The char yield at 800ЊC depended on the structure of the polymer and was in the 39-56% range. The polymers formed by metathesis polymerization showed a 1-3% weight loss in the temperature range 226-371ЊC and decomposed in a single step above 440ЊC. The char yields were higher in these polymers (53-71%) compared to those obtained by thermal polymerization.