Core/shell or nanoshells are a class of nanostructured materials in which a thin coating is deposited on core particles and that can be tailored depending on the type of applications. These nanomaterials show novel properties which are very different from their own single component counterpart. Typically, the synthesis method of core/shell nanoparticles is divided into two phase: solution-based (usually chemical) and gas/vapor-based (chemical or physical). Instead of providing a comprehensive review or compilation of all the synthetic methods, a well-documented example with a short overview of synthesis techniques of core/shell nanoparticles is discussed, special attention has been given to inorganic (metal)/inorganic (silica, non-silica) core/shell nanoparticles. This book also covers the chemical and green synthesis of inorganic (metal)/inorganic (silica, non-silica) core/shell nanoparticles with their various biomedical applications.