This study was performed to investigate the effect of the anti-inflammatory properties of Rhubarb powder against gastric mucosal damage induced by acute exposure to ethanol (5 ml/kg).Twenty five albino rats (Sprague Dawley Strain) weighing between 180-200g have been used for 4weeks.They were divided into two main groups. The first group: Normal control group (negative group, 5 rats) fed on a basal diet for 4 weeks. The second group: Twenty rats were given a single oral dose of 5ml/kg of ethanol following overnight fasting to induce gastric lesions. After that, this group was divided into 4 groups, which were fed different diets (G2: Positive control group, G3: A standard control group, G4: 5% Rhubarb powder and G5: 10% Rhubarb powder). Chemical, biochemical analysis (in serum and gastric mucosa) and histological tests were carried out. These results showed that Rhubarb powder contains a high amount of carbohydrate, ash and protein and contains a moderate amount of fat and fiber. GSH, SOD, GST and CAT serum increased significantly in all groups that were supported by different percentages of Rhubarb powder compared to the positive control group, while MPO serum decreased significantly in all groups that were supported by different percentages of Rhubarb powder compared with the positive control group. Additionally, they showed a significant increase in NO, SOD, GPX and GSH in gastric mucosa in all groups that were supported by different percentages of Rhubarb powder in comparison with the positive control group. However, MDA in mucosa decreased significantly in all groups that were supported by different percentages of Rhubarb powder compared to the positive control group. Regarding the histopathological examination of the stomach, there was a remarkable improvement in all groups whose diets were supported by different percentages of Rhubarb powder compared to the positive control group. Consequently, this study recommends using Rhubarb powder for improving oxidative stress and inflammatory responses because of its bioactive properties.