Charged liquid cluster beam (CLCB) of a precursor solution has been employed to deposit highly [100]-oriented MgO films with full oxygen content on Si (111) and glass in air at a very low temperature (less than or equal to 400 degreesC). Flow-limited field-injection electrostatic spraying was invoked to produce charged nanometer-size drops (liquid clusters) of the precursor solution. This solution was prepared by sol-gel processing of magnesium acetate in ethanol. The morphology, surface atomic ratio of Mg and O, and carbon impurity concentration of the films were studied using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Rutherford backscattering (RBS). The MgO films started to crystallize in the [100] direction below 300 degreesC and became more highly oriented with increasing temperature. Addition of triethyleneglycol to the precursor solution reduced the surface roughness of the films at high substrate temperatures. This technique is applicable to large-area coating.