The aim of this study was to determine the antiulcer and antioxidant activities of Centaurium erythraea L (small centaury) in aspirin (ASA) induced acute gastric ulcer model. The gastroprotective effect of the 50% aqueous-ethanolic small centaury (SC) extract was investigated in rats at a dose of ASA 200 mg/kg body weight. Twenty-one Sprague-Dawley albino rats were divided into three groups of seven rats each as follows: (1) control group; (2) acute ASA-treated group and (3) ASA plus SC group. At the end of the 4-h drug administration, ulcer index, oxidant and antioxidant levels were measured and compared between the groups. The percentage of lesion area to total gastric surface area (ulcer index) was significantly reduced (77%) in ASA plus SC group as compared with acute ASA-treated group. The oral administration of ASA decreased catalase (CAT), reduced glutathione (GSH), and increased lipid peroxidation (LPO) levels. Although myeloperoxidase (MPO) activity was increased by ASA, it was found to be lower in the ASA plus SC group. GSH and Vitamin A levels were determined higher in the ASA plus SC group compared with ASA group. These results suggest that SC extract protects against ASA-induced damage due to its antioxidizing activity.