Growth of MgO single crystals by dynamic chemical vapor deposition has been achieved by generating MgCl 2 vapor by the reaction: MgO ( s) + Cl 2 ( g) + CO ( g) ⇄ MgCl 2 ( g) + CO 2 ( g) and subsequently inducing MgO deposition by adding hydrogen to give: MgCl 2 ( g) + CO 2 ( g) + H 2 ( g) ⇄ MgO ( s) + 2 HCl ( g) + CO ( g) all at 1600 °C and a total pressure of 5 torr. The influence of gas flow rate, temperature and oxidizing potential on epitaxial single crystal growth, needle growth and powder formation due to nucleation in the gas phase is reported. Epitaxial single crystals 1 × 1 × 0.2 cm were grown at rates of 4.2 × 10 ×6 cm/ sec; 1.5 × 0.3 × 0.2 cm needles were grown at linear rates of 2.8 × 10 ×5 cm⧸ sec. Chemical analysis indicated less than 150 ppm by weight, cation impurity, and dislocation densities were 5 × 10 3/ cm 2.