synthetic antioxidants has led to an increased interest in exploration of effective and economical natural antioxidants. The objective of this study was to evaluate the effects of rosemary (Rosmarinus officinalis) essential oil (REO) on oxidative stability of virgin olive oil under accelerated conditions. The REO composition was analyzed by gas chromatography/mass spectrometry. REO and BHT were added to virgin olive oil at 1000 and 100ppm, respectively and their oxidative stability was investigated by using active oxygen method (AOM). Gas chromatography/mass spectrometry analyses of the REO revealed that ?-pinene (17.07%), camphor (9.62%), and bornyl acetate (9.42%) were the major components of REO. REO was significantly effective on oxidation retarding of virgin olive oil. Effect of REO on delaying hydroperoxides formation of virgin olive oil was similar to that of BHT. REO significantly increased induction period, protection factor, and antioxidant power of virgin olive oil. The induction period, protection factor, and antioxidant power of virgin olive oil containing REO (40.01±1.35 h, 1.67±0.05, and 39.96±1.76, respectively) was similar to those of sample containing BHT (44.44 ± 0.23 h, 1.85±0.01, and 45.96±0.05, respectively). Generally, REO is a good natural antioxidant for extending the shelf-life of virgin olive oil.