ABSTRACTBackground: Olfactory loss is a well-known prodromal marker in patients with Parkinson’s disease (PD). Currently, olfactory loss in PD remains untreated; however, studies have shown that deep brain stimulation (DBS) of the subthalamic nucleus (STN), indicated for alleviating motor symptoms, can improve olfactory function. However, the relationship between STN stimulation and olfactory function remains unexamined.