Both monocyte-granulocytapheresis (M-GCAP) and leukocytapheresis (LCAP) are categorized as extracorporeal leukocyte removal therapies (ECCTs). These therapies have been recognized as efficient adjuncts for patients of steroid-resistant ulcerative colitis (UC). This study aimed to consider the adaptation and the limitation of these new therapies from the clinical standpoint based on a case of UC showing strong resistance to high-dose continuous steroid injection therapy. The patient successfully underwent a scheduled colectomy while maintaining remission after applying M-GCAP and LCAP independently. Surgical therapy was chosen because of a deep ulcer in the patient's sigmoid colon, which was assumed to constitute a future risk for perforation. This case suggests that combining ECCT with steroid therapy can maintain such poorly controlled and high-risk UC patients safely for the scheduled colectomy while improving the prognosis by reducing the dosage of steroid efficiently prior to operation.