This study compares the effect of anisotropic structure on the room temperature (23 degrees C) deformation and failure behavior of two distinctly different polymers. One a single phase nematic polymer, PMDA-ODA polyimide [PI] with a glass transition, T-g, near 400 degrees C: the other a previously studied anisotropic two phase molecular polymer composite, isotactic polypropylene [IPP] with a glass transition near 14 degrees C. Although isotactic polypropylene has a two phase crystal-noncrystalline structure its deformation behavior is controlled by the noncrystalline phase. A series of oriented PMDA-ODA polyimide [PI] films are fabricated and their orientation characterized. The present study investigates whether the deformation and failure behavior of these anisotropic single phase nematic PMDA-ODA polyimide films (tested at a very low strain rate at roam temperature) is similar to that previously observed for isotactic polypropylene at its low strain rate failure envelope limit.