Background: Rumex vesicarius l. (polygonaceae) is an eatable herb developing in egypt. The plant has a significant value in folk medicine and it has been used to relieve many diseases. Aim: The aim of the study is to investigate the antitumor activity and evaluate the antioxidant potential of Rumex vesicarius l. extract in experimental animals. Material & Methods: the ethanolic extract of whole plant was prepared and then conducted by high performance liquid chromatography (HPLC) and 2,2-diphenyl-1-picryl hydrazil to evaluate its content and antioxidant potential. The exprimental animals were divided into the following groups: negative control, solvent group, ethanolic extract group, Ehrlich Ascites Carcinoma (EAC) positive group, preventive and therapeutic groups. The antitumor and antioxidant activities were carried out in female albino mice against EAC by measuring viability of EAC cells, nitric oxide (NO), Malondialdehyde (MDA) levels, catalase (CAT) and superoxide dismutase (SOD) activities and Arginase.   Results: the ethanolic extract has a significant antioxidant activity and the HPLC fingerprints showed high contents of phenolic compoundes. Also The extract showed a significant reduction in the volume and count of EAC cells, increasing CAT and SOD activities and reduction in NO, MDA in studied groups compared to positive control. Also, the extract was found to be safe and effective in the treatment. Conclusion: The extract has potent antitumor, antioxidant, and decrease the survival of cancer cells.