the genus indigofera (fabaceae) is used in folk medicine to treat gastrointestinal pain. in this study, we investigated the antiulcerogenic properties of indigofera truxillensis kunth. oral administration of meoh extract did not produce any signals of acute toxicity. the antiulcerogenic activity was assessed in different models of acute gastric ulcers (100% ethanol, piroxicam 30 mg.kg-1, hypothermic restraint stress and pylorus ligature) in mice and rats. the animals were treated with the drugs lanzoprazole (30 mg.kg-1) or cimetidine (100 mg.kg-1) as positive controls depending on the performed model. in another experiment with ethanol-induced ulcers in rats, n-ethylmaleimide (nem), a sulfhydryl group blocker, was also used. the meoh extract, at doses of 250, 500 and 1000 mg.kg-1, inhibited the gastric lesions in all experiments: a) by 62%, 69% and 32%, respectively, in piroxicam-induced lesions, b) by 43%, 71% and 98%, in ethanol-induced lesions, c) by 69%, 64 and 89%, in hypothermic-restraint stress-induced lesions, d) by 73%, 82% and 84%, in pylorus ligature lesions. significant changes in the total gastric acid levels were also found after intraduodenal administration of the meoh extract in the ligated pylorus model. pre treatment with nem reduced partially the antiulcerogenic activity of the meoh extract in ethanol-induced gastric lesions. this result indicates an increase in the levels of non-protein sulfhydryl groups by meoh extract in the gastric mucosa. these results indicate that the meoh extract has antisecretory and citoprotective effects that may be related to the presence of flavonoids detected by phytochemical analysis.