This chapter provides an overview of the efficacy of Schwann cell (SC) and olfactory ensheathing cell (OEC) transplantation to repair the central nervous system (CNS). Remyelination of CNS axons by SCs has been observed in many studies of experimentally induced and naturally occurring pathologic processes. Axons are remyelinated by either endogenous SCs that have migrated into the demyelinated site or by transplanted SCs. Restoration of conduction properties has been studied following remyelination by transplanted SCs. Using the microtransplantation technique to minimize disturbance of the tract architecture, cultured SCs placed into either the cervical corticospinal or ascending dorsal column tracts cause sprouting of both types of axons. A combination strategy involved the transplantation of OECs into the stumps beside the SC bridge after complete transaction. Although OECs do not normally form myelin in the olfactory system, numerous studies have demonstrated that SC-like myelin is produced following the transplantation of OECs.