&NA;In this study the Multi‐Test was applied in 48 patients with inflammatory bowel disease and in 25 normal controls. A significant difference between normal controls and patients with Crohn's disease but not between normal controls and patients with ulcerative colitis was found with regard to anergic status, frequency of positive skin reactions, and size of skin infiltration. The authors conclude that in patients with Crohn's disease a defect exists in the cellular immunity.