The method of leukocytapheresis for ulcerative colitis (UC) by using extracorporeal circulation (on-line system) has been reported. To perform leukocytapheresis, we have applied leukocyte elimination filters for blood transfusion to leukocytapheresis without using extracorporeal circulation (off-line leukocytapheresis system). Four hundred milliliters of peripheral blood was collected and reinfused through a leukocyte elimination filter. This procedure was repeated 5 times, and up to 2,000 ml of peripheral blood was treated. This method has been applied once a week for 5 weeks. We applied the off-line leukapheresis system to a 31-year-old male ulcerative colitis patient. As a result, the frequency of defecation and the dose of medicine were effectively decreased, and endoscopic finding was also improved. Because of the absence of complications observed with the on-line system, the off-line leukocytapheresis system that we have applied to the clinical patient is simple, safe, and useful.