The interest in lipid mediators of inflammation as potential contributors to the pathogenesis of gastric ulcer has increased markedly over the past 20 yr. Although a great deal is known about the actions of mediators such as leukotrienes, thromboxane, and platelet-activating factor in experimental models of ulceration, evidence supporting a role for these mediators in human gastric ulcer is sorely lacking. This review attempts to answer a number of questions regarding the contribution of these mediators to the pathogenesis of gastric ulceration and the possible use of specific inhibitors, antagonists, and dietary manipulation in the treatment of gastric ulcer. Potential directions for future research in this field are suggested as are some of the pitfalls to be avoided in such studies.