ABSTRACTRelations between development of gastric ulceration and changes in motility of the stomach, as recorded by the electrogastrogram (EGG), were studied under conditions whereSs (rats) were exposed to physical (immobilization) and chemical (reserpine) stressors and to the two in combination. Following 36 hrs of the various treatments, all restraint + reserpineSs were ulcerated; 60% of the restraint‐onlySs had lesions; and, only three of ten no‐restraintSs showed gastric damage. The same rank order was obtained for the mean number of lesions per group. There were no significant differences among groups in total acidity of the stomach at autopsy immediately after their experimental treatments. The restraint‐only groups showed a trend toward increased gastric motility during the treatment period, while the restraint + reserpine groups showed a progressive decrease in motility, the divergence leading to statistically significant differences as exposure to the different stressors continued. The results do not support the hypothesis that the experimentally‐produced lesions are related to an increase in gastric acidity; they do support the hypothesis that the ulceration is related to changes in gastric motility, more severe lesions appearing inSs whose motility decreased during the treatment