Due to the enhanced level of performance properties of epoxy materials filled with synthetic diopside and wollastonite, it was of interest to research their chemical resistance and thermal stability. It was stated that the studied composite epoxy materials swell in all typical corrosive media, whereas the most significant swelling was observed in the solutions of sulfuric acid and sodium chloride. Synthetic wollastonite and diopside slightly reduce chemical resistance of filled epoxy compositions in the most common corrosive media. Additionally, it was proven that more porous wollastonite provides for lower chemical resistance of filled materials as compared to diopside. Both synthetic modifiers have thermostabilizing effect on filled epoxy compositions, increasing the characteristic temperatures of mass loss. In this aspect, diopside has a greater impact than wollastonite. Thus, application of diopside is preferrable and recommended for application in anticorrosive and antifriction materials where chemical resistance and thermal stability are of paramount importance.