Parkinson’s disease (PD) is a progressive, neurodegenerative disorder for which there is currently no effective neuroprotective therapy. Patients are typically treated with a combination of drug therapies and/or receive deep brain stimulation to combat behavioral symptoms. The ideal candidate therapy would be the one which prevents neurodegeneration in the brain, thereby halting the progression of debilitating disease symptoms. Neurotrophic factors have been in the forefront of PD research, and clinical trials have been initiated using members of the GDNF family of ligands (GFLs). GFLs have been shown to be trophic to ventral mesencephalic cells, thereby making them good candidates for PD research. This paper examines the use of GDNF and neurturin, two members of the GFL, in both animal models of PD and clinical trials.