Available immunomodulatory and conventional steroid treatment options for patients with progressive multiple sclerosis (MS) only provide limited symptomatic benefit. We performed an open trial on the short-term and long-term efficacy and safety of repeated intrathecal application of the sustained release steroid triamcinolone acetonide (TCA) in 36 progressive MS patients. Six TCA administrations, performed every third day, reduced the EDSS score (initial: 5.6+/-0.93 [mean+/-S.D.]; end: 4.9+/-1.0; p<0.001) and increased the walking distance (WD) (initial: 294+/-314 m; end: 604+/-540 m; p<0.001). Twenty MS patients continued intrathecal TCA treatment with one TCA injection performed with a variable frequency ranging from 6 to 12 weeks. Both EDSS and walking distance remained stable in these patients until the end of the follow-up investigation period. No serious side effects occurred. We conclude that repeated intrathecal TCA injection provides substantial benefit for progressive MS patients with predominantly spinal symptoms.