Publisher Summary This chapter discusses a critical survey of what is known or believed concerning some aspects of the relationship between the endocrine system and the stomach. The subject matter to be considered has a distinct clinical bias because much of the work performed in this field has stemmed directly from the belief that the incidence and behavior of chronic peptic ulcer may be influenced by several of the endocrine glands. The evidence for these beliefs is examined, and the possible mechanisms by which the endocrine system may influence the occurrence and behavior of peptic ulcer are considered. It has long been suspected that the endocrine system might influence the alimentary tract, and various aspects of this relationship have been studied in the last two decades. This review attempts a critical survey of what is known or believed concerning some aspects of the relationship between the endocrine system and the stomach, The subject matter to be considered has a distinct clinical bias because much of the work performed in this field has stemmed directly from the belief that the incidence and behavior of chronic peptic ulcer may be influenced by several of the endocrine glands.