ABSTRACT: The use of photoelastic stress analysis has been shown to illustrate the stress distribution for various prefabricated and cast post systems. However, there are limited studies investigating the photoelastic stress distribution for endodontic post/core systems. This study compares two different core materials (Ti-Core and GC Miracle Mix) supported by two different endodontic post systems (Flexi-Post and Para-Post) for photoelastic stress distribution in an oblique loading condition with a 26 degree angle at 20 pounds. Four groups of post/core systems blocks of photoelastic materials were prepared with simulated endodontic canals(using a plastic that approaches the strength of dentin), and the specimens(photoelastic block/cemented post/core combinations) were then photographed in the unloaded and loaded states. Minimal stresses were observed for all post/core combinations in the unloaded state. The specimens prepared with the multi-tiered, Flexi-Post clearly distributed stress symmetrically and coronally in the loaded oblique state, while the specimens with the single tiered Para-Post showed asymmetrical apically and coronally stress patterns. Post/core combinations with Ti-Core composite were more stable than post/core combinations with GC Miracle Mix glass ionomer. The symmetric, even stresses for the Flexi-Post/core systems are more favorable than the asymmetric, uneven stresses for the Para-Post/core systems. Post/core combinations with Ti-Core a titanium reinforced composite are more stable and favorable than post/core combinations with GC Miracle Mix glass ionomer.