Doxorubicin (DOX) is a common antineoplastic drug, prescribed single or combined with different agents. Nevertheless, DOX could adversely affect normal cells; therefore, its clinical use is limited. The present research aimed to investigate the genotoxic effects of DOX on liver tissues, the preventative role of Omega-3 against DOX-induced hepatotoxicity in male albino rats and to explore the advantage of comet assay to predict the response of patients to chemotherapy. Rats (n=60) were divided into 4 groups. The control group was orally administered 0.5 ml of corn oil. Group 2 was injected intraperitoneally weekly for 4 weeks with DOX (4mg/kg b.w). Group 3 was treated daily with omega-3 for 30 days (400mg/kg b.w). Group 4 were treated with DOX and omega-3 at the same doses as group 2 and 3, respectively. Many techniques were used to estimate the effect of omega-3 against aDOX. Comet assay showed that DOX treatment caused significant damage to DNA in both the liver and blood. The biochemical tests showed elevation in serum ALT, AST, malondialdehyde (MDA), nitric oxide and reduction of the antioxidant enzymes (catalase and superoxide dismutase) that were caused by DOX. Histologically, the liver showed disarray, hyperemia, coagulative necrosis, and leukocytic infiltration. Treated animals with omega-3 along with DOX showed a decreased rate of DNA damage. Moreover, better biochemical changes. The present study indicated that omega-3 had protective and antigenotoxic effects against DOX-induced liver injury. Moreover, comet assay showed a precise diagnosis of liver and blood genotoxicity.