Major developments have taken place in the field of single crystal synthesis by microwave plasma chemical vapor deposition (MPCVD). High-quality single crystal diamond blocks, anvils, and plates have been produced by employing this microwave plasma technology. Significant process improvements in synthesis rates, diamond quality, and large diamond crystal size appear possible with the design of optimized high-power higher-pressure MPCVD diamond reactors. Deposition process variables such as plasma gas temperature, plasma density, electron temperature, doping, substrate temperature, and power source mode are important operating parameters for CVD diamond growth. The identification of defects, impurities, and crystalline quality is also critical for the growth optimization process. This entry highlights developments in MPCVD reactor technology, single crystal CVD diamond growth process conditions, and diamond characterization, which are useful for understanding diamond synthesis, bulk properties, and its applications.