PURPOSE: This study evaluated some mechanical properties of 2 newly introduced, addition-type silicone prosthetic elastomers (Cosmesil and Episil). MATERIALS AND METHODS: The properties evaluated were tensile strength, modulus at 100% elongation, elongation at break, tear strength, and hardness. The properties tested were selected because of their clinical significance for fabricating facial prostheses. RESULTS: Episil showed greater tensile strength (P = 0.0002), elastic modulus (P = 0.0001), hardness (P = 0.0002), and tear strength (P = 0.0004) than Cosmesil material. Cosmesil exhibited a higher elongation at break (P = 0.0002) than Episil. CONCLUSION: Cosmesil and Episil showed reasonable properties as facial prosthetic elastomers and neither was superior for all properties tested. Both materials showed favorable combinations of elongation at break and tear strength.