The stabilization of polyvinyl chloride polymer has a great concern for researchers due to its high instability in the environmental conditions of heat and ultraviolet arrays. Herein, three metal complexes of Schiff base ligand were prepared and their chemical structures were confirmed using elemental analysis, FTIR, 1H-NMR, and UV/Vis spectra. The prepared metal complexes were incorporated in PVC as photo-stabilizers. Only 0.5% by weight of these prepared Schiff bases metal complexes was blended with the PVC polymer to form films with a width of (50 μm). The prepared samples were exposed to ultraviolet irradiation time was varied ranging from 0 to 300 h and the impact of irradiation scheduled upon the PVC stabilization was examined each 50 h. The degree of degradation of PVC in the presence and absence of the different stabilizers was determined using various techniques, including the degree of oxygenated compounds formed, degree of unsaturation, viscosity, and degree of deterioration. The results showed that in the native PVC, the degradation progressively increased over time at the conditions of the experiments. The addition of the stabilizers decreased the degradation considerably. The formation of carbonyl, hydroxyl, and unsaturated intermediates was decreased in the presence of Cu-L, and Ni-L. While Fe-L stabilizer showed weak efficiency. The reasons for the stabilization and the mechanism of the degradation/stabilization processes were discussed based on the electronegativity of the metal ions and the antioxidant activities of the different metal complexes.