Western parsley (WP), a culinary herb, has been reported to display significant antioxidative properties and to contribute to the elimination of heavy metals, but little information is available regarding its effect over food storage stability. In this study, the effect of this plant on the oxidative stabilities of food was investigated as compared with the synthetic antioxidant ethoxyquin (EQ) under accelerated oxidative stress. Headspace oxygen consumption, formation of primary and secondary oxidation products, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, were used as the parameters. Oxidative stabilities of food increased significantly (P ≤ 0.05) with addition of WP, revealing potent antioxidant activities of WP for stabilization of food over a long storage period. Our results suggested that the synergistic action of the phytochemicals may be contributing to the improved oxidative stabilities. According to these results, WP, a commonly consumed herb, can be used as an alternative to synthetic antioxidants in the long-term storage of food.