In recent years, prophylactic usage of natural products and tendency to resort to alternative medicine has increased rapidly. Henna (Lawsonia sp.) has been used not only cosmetically but also medicinally in Turkish population. Among the studies of henna's antifungal, anti-microbial, tuberculostatic and antitumoral effects come on the science. In this study, we planned to research the effect of Lawsonia inermis that is an oxidant agent against development of cancer, by constituting peritonitis carcinomatous with Ehrlich ascites cells. The animals were divided to three groups and Lawsonia inermis extract and tap water were given to mice for 5 days. After 5 days, all of animals were decapitated by cervical dislocation and their liver tissues were sampled to measure reduced glutathione (GSH) level. Mean Survival Time (MST) and Average Survival Time (AST) were calculated; peritoneal liquid pH was measured; Ehrlich Ascites Carcinoma (EAC) cells were counted with hemocytometer. At the result, the longest life period was detected on the group which was given 10 mg/kg/day Lawsonia inermis. In group 2 and 3 which were given Lawsonia inermis following to forming Ehrlich ascites carcinoma, total number of cancer cell decreased. The scaled pH levels belonging to group 2 and 3 changed into alkaline compared to that of group 1 (pH = 6.2). Glutathione levels of liver tissue were determined to decrease in group 2 and 3 in comparison with group 1. In conclusion, Lawsonia inermis may lead cells to apoptosis related to deficiency in detoxification of intracellular radicals.