Much has been learned from recent clinical trials exploring cell transplantation as a means to treat Parkinson's disease. Additionally, much information is being gathered in the science arena on the method of cultivation and expansion of neural stem/progenitor cells as well as catheter and cell delivery methodology. Cell replacement remains a potential promising treatment option for Parkinson's disease, however several obstacles must be overcome in order to achieve successful outcomes in future clinical trials. Hurdles include but are not limited to the identification of a reliable method of cultivation and expansion of neural stem/progenitor cells, the optimization of methods for cell delivery and the optimization of location or locations for transplantation.