Although the precise link is not completely understood, eosinophilic gastrointestinal diseases have been shown to be highly associated with atopy. Oral tolerance describes the specific suppression of immune responses to an antigen by prior administration of the antigen by the oral route. Like other allergic gastrointestinal diseases, eosinophilic gastrointestinal disorders may result from a loss of oral tolerance or a failure in the induction of tolerance. Further study to clarify the role of tolerance in the development of eosinophilic gastrointestinal diseases can help identify potential prevention strategies and therapeutic targets.