New epoxy resins obtained from a series of bis(4,5-epoxytetrahydrophthalimides) and three different dicarboxylic diacids were prepared and characterized by spectroscopic techniques and thermal analyses. Homopolymerization of epoxy groups was observed as a parallel process to the polycondensation reaction. Using Epiclon B with a tertiary amine and hexamethylene diisocyanate as hardeners, we studied the reaction of epoxy groups and hydroxylic groups attached to the cycloaliphatic moiety in the main chain. No exotherms were clearly detected by DSC, and during the curing process, only increases in the T-g values were observed. These cycloaliphatic epoxy polyesters have similar thermal characteristics to related aromatic epoxy polyesterimides, but have better processability.