Background : Lactuca sativa (LS) is a member of lactuca genus and the Asteraceae family. To its usual purpose as an edible leafy vegetable, lettuce has had a number of uses in ancient times as a medicinal herb. Depending on the variety, lettuce is an excellent source vitamin K and vitanin A. Methods and Results : The objective of this study is to find out the antioxidant and oxidative DNA damage prevention capacity of LS for both water and ethanol extract. The total phenolic and flavonoid contents have been estimated in this study. The extracts have been tested to assess the 1, 1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2ʹ -azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and nitrite scavenging activity. We have also evaluated the reducing power activity of LS. LS extracts showed a good radical scavenging activity on DPPH and ABTS free radical as concentration dependent manner. The IC50 values on DPPH radical scavenging activity were 0.75 mg/mL and 0.54 mg/mL for water and ethanol extract respectively. ABTS radical scavenging activity ranges from 38-89 % for water extract and 33-96% for ethanol extract. Although ethanolic extract showed a higher radical scavenging activity as compared to the water extracts. All the extracts exhibited reducing power activity, dose dependently. Moreover, when the DNA was treated with the extracts, supercoiled DNA was restored in a concentration-dependent manner. Conclusion : According to the results, we suggest that LS contains considerable amount of phenolic and flavonoid content and could be used as a source of natural antioxidant substances and oxidative DNA damage preventer.