II-VI oxides ternary alloys have attracted considerable interest of the scientific community due to the possibility of modulating their interesting optoelectronic properties. Despite this interest, MgCdO has been poorly studied. In this work, by using the metal organic chemical vapor deposition method at low pressure, we have analyzed the synthesis of thin films of this alloy. Thus, for a fixed metal-organic precursors content, a change from Mg1-xCdxO (Mg-rich phase) to Cd1-xMgxO (Cd-rich phase) has been induced when decreasing the growth temperature. The temperature range where both phases coexist has been particularly analyzed. Using X-ray diffraction analysis and scanning electron microscopy, a structural and morphological study of the samples has been carried out. In addition, the composition of the alloy has been measured by using energy dispersive X-ray analysis, and the behavior of the lattice parameter as a function of Cd content has been studied.