We examined the expression of glycogen synthase kinase-3beta (GSK-3β) in the cerebrospinal fluid (CSF) of Parkinson`s disease (PD) patients. GSK-3β is a critical intermediate in pro-apoptotic signaling cascades that are associated with neuro-degenerative diseases, including PD. Because CSF contains proteins and metabolites of brain origin, and GSK-3β levels are increased in brains of PD patients, we decided to measure GSK-3β levels in CSF samples from PD patients. We observed that neither GSK-3β nor pGSK-3β (Ser9) was altered in PD patients. Our results suggest that, although GSK-3β plays a role in the pathogenesis of PD, its CSF levels were unchanged.