In this study, lemon verbena essential oil as a natural antioxidant was used to increase the stability of sunflower oil, and stabilization effects in terms of storage conditions were compared with synthetic antioxidant (BHT). For this purpose, the antioxidant activity of the essential oil was determined by DPPH assay and β‐carotene bleaching method. Then, lemon verbena essential oil (0, 400, 800, and 1,600 ppm) was added to sunflower oil without synthetic antioxidant and stored at 60°C for 60 days. Results from different parameters (peroxide value, free fatty acid, iodine value, total polar compound, carbonyl value, conjugated dienes, and oxidative stability index) were in agreement with each other, suggesting that lemon verbena essential oil (1,600 ppm) could act better than BHT in inhibition of lipid oxidation in sunflower oil and can be used as predominant alternative of synthetic antioxidants.