Background: Formononetin (FMN), one of the major isoflavones in red clover, has been shown to possess antioxidant, anti-inflammatory, antitumor, neuroprotective, and cytoprotective activities. However, there is no report on the gastroprotective effect of FMN against ethanol-induced gastric ulcer. Objective: Excessive alcohol consumption can lead to gastric ulcer, and the purpose of the present study was to examine the protective effect of FMN on mucosal lesions induced by ethanol. Materials and Methods: Fasted rats were orally administered with FMN at different doses, omeprazole (20 mg/kg), followed by intragastrical ingestion of ethanol (5 ml/kg) after 1 h and sacrificed after 1 h of exposure. Gross microscopic, macroscopic, and biochemical assays were scrutinized. Results: Compared with ethanol, FMN pretreatment showed a significant increase in the gastric levels of glutathione while decreased the malondialdehyde content remarkably. FMN pretreatment also bestowed the cytoprotective efficacy against ethanol-induced ulceration by reestablishing the decreased level of nitrite (NO). Furthermore, in histopathological sections, reduced pathological changes of gastric lesions were markedly observed in the FMN-pretreated groups compared with those in the ethanol group. Western blot analysis showed upregulation of BcL2 while downregulation of Bax in FMN-pretreated gastric tissue of rats. Conclusion: These results indicate that FMN exerts gastroprotective effects through the antioxidative, anti-inflammatory, and antiapoptotic that are probably mediated by enhanced NO release, suggesting its therapeutic use to treat gastric ulceration by preserving mucosal glycoproteins and diminishing oxidative stress.