The effect of hyperbaric treatment (between 0.3 and 0.9 MPa)at 20◦C on antioxidants and antioxidant activity was evaluated incomparison to atmospheric pressure at 20◦C and the commercialstorage temperature (13◦C). The lycopene content of hyperbaric-treated tomato fruit was noticeably inhibited during the treatmentwhereas its accumulation was enhanced during ripening comparedto untreated fruit (20◦C control). In general, hyperbaric treat-ment did not appreciably influence ascorbic acid and total phenoliccontent of tomato fruit. However, hyperbaric pressure at 0.9 MPainduced the accumulation of significantly higher amounts of bothascorbic acid and total phenolic content in tomato compared tothe 13◦C treatment. Antioxidant activity determination showedthat even though lycopene content was significantly affected bytime and treatment conditions, no significant difference in LAA wasencountered. The trend of HAA was in accordance with the resultson ascorbic acid and total phenolic content. Generally, the HAA increased as time progressed and did not noticeably differ amongtreatment conditions. However, after ripening, it is likely that thehyperbaric pressure at 0.9 MPa caused a significantly higher HAAcompared to 0.1 MPa at 13◦C. Overall, hyperbaric treatment at 20◦Chas potential to extend tomato shelf-life during short treatmentdurations without adverse impact on quality during ripening. Morestudy is required to determine optimal pressures and treatmenttimes to produce the highest quality.