Stress distribution studies can be helpful in determining the appropriate diameter and length of endodontic posts for specific teeth in select occlusal relationships. This study selected the finite element method to predict distribution of stresses in dentin of an endodontically treated tooth restored with cast post and cores with various post dimensions. Peak dentinal shear stresses occurred adjacent to the post at mid-root. Peak shear stresses were elevated as the length of the post decreased. Peak dentinal tensile stresses occurred in the gingival third of the facial root surface, whereas peak dentinal compressive stresses were evident in the gingival third of the lingual root surface. The distribution of tensile and compressive stresses was not affected with variation in the dimensions of the posts.