Corticosteroids have been used for decades in the treatment of inflammatory bowel disease. Despite considerable information on the clinical response to corticosteroids in inflammatory bowel disease, much less is known concerning corticosteroids' effects on the underlying immunopathology of the disease. In this review, we discuss the known immunologic actions of corticosteroids: their effects on eicosanoid production and on modulating the humoral and cellular immune response. After reviewing the postulated immunological aberrations in inflammatory bowel disease, we speculate on the specific immunologic effects of corticosteroids in this disease.