'Marjoram,' Origanum majorana L., a culinary aromatic medicinal herb is known to possess various therapeutic properties. We evaluated the antiulcerogenic activity of the ethanol extract in hypothermic restraint stress-, indomethacin-, necrotizing agents- (80% ethanol, 25% NaCl and 0.2 M NaOH) induced ulcers and basal gastric acid secretion using pylorus ligated Shay rat-model. Marjoram at doses of 250 and 500 mg/kg of body weight, significantly decreased the incidence of ulcers, basal gastric secretion and acid output. Furthermore, the extract replenished the ethanol-induced depleted gastric wall mucus and nonprotein sulfhydryls (NP-SH) contents and significantly lowered the increase in the concentration of malondialdehyde (MDA). Ulcer preventing potential was further confirmed by histopathological assessment. An acute toxicity test showed a large margin of safety of the extract in mice. The phytochemical screening of aerial parts of marjoram revealed the presence of volatile oil, flavonoids, tannins, sterols and/or triterpenes.