The influences of acetic acid addition to Mg-methoxide on the stability of the precursor and the crystallization behavior of sol-gel-derived MgO nano-powders and thin films were investigated using X-ray powder diffraction, transmission electron microscopy, Fourier-transformed infrared spectroscopy, and thermogravimetry. The addition of acetic acid enhanced the stability of the alkoxide against precipitation. Moreover, during postheat treatment of the gel powders treated with acetic acid, a significantly lowered crystallization temperature (250 degrees C) was observed as compared to the untreated counterpart (350 degrees C). The low-temperature crystallization of MgO, induced by the modification of Mg-methoxide with acetic acid, was related to the decomposition of organics at a lower temperature. These results could be explained in terms of the decrease of the O-R bond strength depending on the increase in the alkyl group size. MgO thin films having a high degree of crystallinity were successfully obtained from the Mg-methoxide treated with acetic acid at 300 degrees C. The low-temperature crystallization of sol-gel-derived MgO thin films showed the feasibility for their application as a protective layer in alternative current plasma display panel cells.