The safety and tolerance of treatment with autologous pluripotent mesenchymal stem cells (MSC) in multiple sclerosis were assessed in eight patients using autologous MSC harvested from the red bone marrow. MSC growth, immunophenotypes, and karyotypes, sterility, the absence of contaminating hematopoietic cells, chromosomal aberrations, and signs of aging were monitored during cultivation. Introduction of MSC into patients' blood was performed in accordance with a protocol consisting of short intravenous infusions at a dose of 2·106 per kg body weight, once every 30 days. Treatment duration was 4-8 months. Treatment efficacy was evaluated at 4, 8, and 12 months. Repeated intravenous infusions of autologous MSC were tolerated well by all patients and no significant side effects were seen either in the early or the late post-treatment phases. A clear positive effect was seen in some cases within two months from the start of treatment. Five of eight patients showed 0.5-point improvements on the EDSS at four months. At 12 months, observations revealed improvements on the EDSS by 0.5-1 point in six of the eight patients, stabilization in one, and progression in one. These results provide evidence of the safety of this treatment and its moderate clinical efficacy in multiple sclerosis patients who are incurable using traditional approaches.