Ulcerative colitis (UC) together with Crohn's disease (CD) constitute idiopathic inflammatory bowel diseases (IBD) of the gut. The etiology of IBD is poorly understood, but autoimmune-disturbance has been suggested to play an important role in this incurable disease. Extracorporeal leukocyte removal therapy (ELRT) is the latest adjunct for IBD patient refractory to steroids, and it aims at suppressing immunological response by removing circulating leukocytes, especially granulocytes, from the blood stream. The present paper reviews the latest evidences in order to propose the current status of ELRT in the therapeutic strategy for IBD, especially for UC and CD. Clinical experience so far suggests that ELRT has superior efficiency as a non-pharmacological immuno-modulative therapy for steroid resistant UC patients before submission to colectomy. Moreover, ELRT has been proven to be a safe therapy compared with other current medications for severe UC.