Resin composites are increasingly used in dental restorative procedures due to their appropriate esthetic mechanical, , and physical properties as well as improvements in adhesive dentistry Various different resin composite restorative materials are continuously being introduced to the market. Their composition and mechanical properties, largely, influence their clinical performance. Materials and methods : Three resin composite restorative materials ( Tetric N – Ceram, ACTIVA, and the hybrid resin composite Te - Econom Plus ) were investigated regarding fracture toughness and micro-hardness. Thirty disk shaped samples ( n = 10 / group ), were prepared, light cured and finished and polished. The surface micro-hardness was assessed using a Digital Display Vickers Micro-hardness Tester. Both fracture toughness and micro-hardness were assessed using the indentation technique with heavy loading. Results : Regarding both fracture toughness and micro-hardness, the highest means plus or minus SD were recorded by Tetric N – Ceram, followed by Te – Econom Plus, while ACTIVA demonstrated the least.