6 patients with Crohn's disease for 1-14 years have been treated with plasmapheresis for periods of up to 6 months. The symptoms of the one newly diagnosed patient were controlled by plasmapheresis alone, and 5 steroid-dependent patients were able to reduce their steroid requirements. During the study period, 13 clinical relapses were managed without increasing steroid dosage. There was evidence of circulating soluble immune complexes in all the patients and these levels were lowered by plasmapheresis. A possible role of plasmapheresis in the management of Crohn's disease is discussed.