Natural or syntheticcoumarins showed gastroprotective and antiulcer activity in animal models. In this study, we have synthetized twenty coumarins using classic methods to evaluate their gastroprotective effects on the ethanol/HCl-induced gastric lesion model in mice at 20mg/kg. Among the coumarins synthetized, compounds 6 and 10 showed the greatest gastroprotective activity being as active as lansoprazole