Long-term lymphocytapheresis (LPH) therapy was applied in 9 patients with a relapsing-remitting course of multiple sclerosis (MS) and a high frequency of bouts. The therapeutic scheme included series of 4 LPH within 8 days, which were repeated every 6-8 weeks during 1 year or longer, until the myelin-reactive T cell test--which was used for immunological control--became normal. Altogether, the therapy was well tolerated, but severe problems with the veins occurred in 2 of the 9 patients. No bouts during LPH therapy were seen in 7 of the 9 patients. The 3 patients with the shortest duration of the disease showed an improvement of the Kurtzke scale. No relapses or a reduced relapse rate--compared to the time before LPH therapy--was observed in 6 of the 9 patients during the follow-up period of up to 23 months. Conclusively, long-term LPH therapy seems to be recommended as an alternative to the continuous administration of immunosuppressive drugs, especially for active cases of MS with a short duration of the disease.