Regional enteritis does present therapeutical problems because of the unpredictable course of this disease. 162 patients were operated upon in the Surgical Department of the University of Mainz Medical School between 1964 and 1976. Medical and surgical treatment of these patients has been rather different due to the heterogenity of the patient group. Curative therapy of regional enteritis does not exist. Medical treatment is aimed at converting the active form of the disease into an inactive, 'burnt out' form. One therapeutic regimen widely used is the combination of salazosulfapyridin and corticosteroids, another regimen is the combination of azathioprine and prednisolone. Surgery is indicated when complications arise and after medical treatment has failed. The optimal approach is resection of the afflicted part of the intestine. Even after surgery prognosis is doubtful and depends upon the activity of the disease in each individual case.