To certify the feasibility of leukapheresis, 37 ulcerative colitis (UC) patients, who had failed to recover by conventional treatment were enrolled in this treatment. Imugard (Terumo Co., Ltd., Tokyo Japan) or Cellsorba (Asahi Medical) filters were used. The schedule was one session weekly for 3 weeks and then twice monthly for 2 months. The laboratory tests performed were complete blood count, complements, immunoglobulins, and lymphocyte subsets. Endoscopic examination was done before and 3 months after initiation. Thirty-four of thirty-seven patients had some beneficial effects, and no patient's condition deteriorated. Corticosteroids were tapered or stopped in 18 patients out of 21. Seventeen of twenty patients experienced endoscopical remission. In laboratory data, leukocytes decreased with time. The C-reactive protein (CRP) levels and erythrocyte sedimentation rates (ESRs) improved. The percentage of CD3+HLA-DR+ cells, CD8+HLA-DR+ cells decreased. Six patients discontinued the treatment. Three of them showed no favorable effects. No severe side effects were observed. This treatment is cost effective and will be a feasible treatment.