Oral administration of aqueous extracts of Zizyphus lotus root barks (50-200 mg/kg) leaves (50-200 mg/kg) and fruits (200-400 mg/kg) produced a significant (p<0.01) and dose dependent inhibition to the acute ulcer induced by HCl/ethanol solution. The methanolic (MeOH), ethyl acetate (EtOAc) and chloroformic (CHCl(3)) leaves extracts when administered orally at the dose of 200 mg/kg, exhibited a significant (p<0.01) inhibition of gastric lesions by 45%, 76% and 33%, respectively. Indeed, methanolic and ethyl acetate root barks extracts significantly reduced the gastric lesions by 47% and 41%, respectively. While the chloroformic root barks extract had no significant activity (19%). The effect of all extracts was compared with cimetidine (100 mg/kg, 62%) and omeprazole (30 mg/kg, 93%). Volume, pH and acidity of gastric juice were studied in pylorus-ligated rats. Root barks (200 mg/kg, p<0.01), leaves (200 mg/kg, p<0.01) and fruits (400 mg/kg, p<0.05) aqueous extracts showed significant reduction of gastric juice secretion in pylorus ligated rats, whereas the other extracts did not show any significance. Thus, Zizyphus lotus extracts act essentially as cytoprotective agents, which support the antiulcer effect of this plant in the traditional medicine.