Piracetam, used clinically for cognitive disorders, was found to have significant anti-ulcerogenic activity against immobilization stress- and aspirin-induced gastric ulcers in rats. The anti-ulcer effect of piracetam was exerted by augmentation of mucosal resistance. This was indicated by the significant attenuation of the decrease in total carbohydrate: protein ratio induced by aspirin. It also reversed the marked increase in gastric juice protein and DNA induced by aspirin, indicating that piracetam attenuated the augmented mucosal cell exfoliation induced by the ulcerogen. The drug also increased gastric mucosal serotonin concentrations. Piracetam, thus appears to have a profile of activity associated with cytoprotective agents.