Astaxanthin, a Xanthophyll carotenoid, has strong antioxidant properties. Some studies have shown the effectiveness of this compound on the prevention and treatment of cancer. Therefore, the aim of this study was to evaluate the effects of astaxanthin on induction of apoptosis and antioxidant activity in the LS-180 cell line. In this experimental study, after the treatment of LS-180 50, 100 and 150 lm of Astaxanthin for 24 h, the expression levels of Bax, Bcl2 and Caspase3 genes were investigated by Realtime PCR. Also, the level of malondialdehyde, as an indicator of oxidative stress and activity of antisuperoxide dismutase enzymes, catalase and glutathione peroxidase was investigated by colorimetric methods. The results showed that astaxanthin increases the expression of Bax and Caspase3 genes and decreases that of Bcl2, thereby, inducing apoptosis and inhibiting growth and proliferation of the cells. Additionally, reduction in the levels of malondialdehyde was evident with a significant elevation in antioxidant activity mediated by the action of superoxide dismutase, catalase and glutathione peroxidase. These results suggest that astaxanthin has the potency to induce apoptosis in LS-180 cells by increasing the expression of apoptotic genes and activity of antioxidant enzymes. Thus, astaxanthin has potential in the prevention and treatment of cancer. ARTICLE HISTORY