Metallic materials are used in many medical devices due to their high mechanical reliability and their excellent strength and toughness. They account for more than 70% of internally implantable devices (implants). This book helps understand the necessity and problems of metal materials used in medical applications. This book was written with the goal of helping students learn the essentials of metallic biomaterials and acquire knowledge that can be applied in a progressive manner. The target audience for this book are students, graduate students, engineers, medical doctors, and others who need knowledge about metallic biomaterials.