Lysosomal storage diseases (LSDs) are rare, inherited enzyme deficiencies which frequently cause progressive mental and/or physical deterioration and early death. Hematopoietic stem cell transplantation (HSCT) is a useful treatment for some, but not all, LSDs. Unfortunately, LSDs with primarily neurological pathology do not respond to HSC transplantation. Direct transplantation of neural stem cells (NSCs) into the brain is currently under investigation as a possible treatment of LSDs that affect primarily the central nervous system (CNS). However, those LSDs with both systemic and neurologic manifestation will likely, based on current clinical knowledge, require a combined transplantation approach, with both hematopoietic and neural stem cells, to have significant therapeutic effect.