A simple solution route employing the reaction of magnesium acetate tetrahydrate ((CH3COO)2Mg.4H2O) and hexamethylenetetramine (C6H12N4) has been demonstrated to successfully grown MgO thin film on both Mg and MgO substrates at two different temperature i.e 90 °C and 150 °C for 4 h. Morphological observations revealed that the porous structure of MgO film was obtained on Mg substrate while sheet-like structure film was observed when using MgO substrate. EDX indicated only Mg and O were present in all films. The MgO bandgap obtained varies with type of substrate used and temperature. The MgO film growth on Mg substrate bandgap increased from 5.18 eV to 5.27 eV with temperature increased from 90 °C to 150 °C. Similar increased was also observed with MgO film growth on MgO substrate. However the results obtained are well below of MgO bulk energy bandgap. This was probably due to non-stoichiometry of deposited layers and crystallinity of the samples as shown by EDX and XRD results respectively.