MgO films were prepared on Si(100) and soda-lime glass substrates by using plasma-enhanced metal-organic chemical-vapor deposition. Various ratios of the O-2/(CH3MgOBu)-Bu-t gas mixture and various gas flow rates were tested for the film fabrications. Highly (100)-oriented MgO films with good crystallinity were obtained with a 10 seem (CH3MgOBu)-Bu-t flow without an O-2 gas flow. About 5% carbon was contained in all the MgO films. The refractive index and the secondary electron emission coefficient for the best quality film were 1.43 and 0.45, respectively. The sputtering rate was about 0.2 nm/min for 10(11) cm(-3) Ar+ ion density. Annealing at 500 degrees C in an Ar ambient promoted the grain size without inducing a phase transition.