Various clinical trials of gene therapy for Parkinson's disease (PD) are finally underway. The vehicle used mainly for gene delivery to the human brain is recombinant adeno-associated viral (rAAV) vector, which is nonpathogenic and non-self-amplifying. At present, the gene therapy approach is not the best way for the treatment of PD patients, but we believe that the further progress is anticipated toward making this strategy a therapeutic option for PD in the future. This article will review currently ongoing clinical trials of PD gene therapy and then introduce our studies about the gene therapy for PD.