Abstract The myelin-associated protein Nogo-A is a well-known inhibitor for axonal regeneration and compensatory plasticity, yet functions of endogenous Nogo-A in oligodendrocyte differentiation are not as clear. As oligodendrocyte matures, its processes branch and eventually form lamellae that ensheath target axons. The present study examined the effects of decreased levels of Nogo-A on the development of oligodendrocytes. The siRNA mediated Nogo-A silencing in these cells did not change their proliferation rates identified by BrdU incorporation assay and neither the expression of stage specific oligodendrocyte makers as identified by qRT-PCR and immunostaining. But knockdown the expression of Nogo-A significantly enhances the process branching complexity by Sholl analysis. Current results suggest a novel role for Nogo-A in maintaining a restricted branching phenotype in oligodendrocytes process outgrowth, which is a key step towards myelin membrane sheet formation and myelination.