Cell transplant therapy for Parkinson's disease (PD) has been in use for over 2 decades as an experimental treatment. Different cell types have been proposed as better therapeutic alternatives. However, source availability and therapeutic value of the transplants as compared to current pharmacological options have precluded the use of this kind of surgery in the majority of PD patients. In this article, we discuss the suitability of different types of stem cells for PD therapy, the requirements that the donor cells should fulfill in order to improve upon current methods, and propose alternatives for evaluating the efficacy of PD cell therapy.