Objective:The present investigation was performed to evaluate the antiproliferative and antioxidant activity of Aegle marmelos leaves in Dalton's Lymphoma Ascites (DLA)-bearing mice.Materials and Methods:The DLA cells maintained in vivo in Swiss albino mice were used for developing ascitic tumor in mice by intraperitoneal transplantation. The standardized 50% ethanolic extract of A. marmelos leaves (AMEE) was administered intraperitoneally in dose levels 200 and 400 mg/kg, after 24 hours of tumor inoculation in mice for two weeks.Results:The AMEE treatment significantly prevented (P<0.001) the increase in body weight due to tumor cell growth and increased the mean survival time of the tumor-bearing mice as compared to the untreated DLA control mice. The treatment of DLA-bearing mice brought down the Alanine Aminotransferase (ALAT), Aspartate Aminotransferase (ASAT), and alkaline phosphatase to normal levels. The extract decreased the levels of hepatic lipid peroxidation and increased the levels of hepatic antioxidants Glutathione, Superoxide Dismutase (SOD), and catalase. All the changes observed with AMEE treatment were dose dependent.Conclusion:The hydroalcoholic extract of A. marmelos exhibits strong antitumor and antioxidant activities in DLA-bearing mice.