Objective: IFN gamma is a pleiotrophic cytokine which is produced by a variety of immune cells in the development of disease such as multiple sclerosis. There are supporting evidences implying a role for NO in tissue damage during demyelinating diseases through LPS induction. Recent studies showed that the influence of IFN-g and/or LPS on survival and rat oligodendrocyte progenitor cells (OPCs) differentiation. In this study we investigated the effects of these factors on survival of human OPCs. Materials and Methods: OPCs were grown for 1 day in Serum free medium were treated for 12 and 24 hours with IFN-g or a combination of LPS and IFN-g at different concentrations and survival of these cells was assayed utilizing MTS. Results: As shown in data, LPS with 15 μg/ml and IFN-g with 100 ng/ml, either alone or in combination, reduced proliferation of the cells significantly. Conclusion: The data presented in our study provide evidence for direct action of anti-inflammatory cytokines on oligodendrocyte precursor cells survival.