Background: There are over 10 million patients living with Parkinson’s Disease (PD) worldwide, over 1 million of which are in the United States. Diagnosed PD patients with a history of emergency department (ED) utilization are likely to have high rates of future ED encounters, but ED utilization patterns of patients prior to PD diagnosis is unknown. This is a major gap in the body of PD and emergency medicine literature with real-world, global health consequences: early recognition of PD facilitates disease-delaying interventions, more effective therapeutic options and eligibility for clinical trials not available to those diagnosed at later, irreversible stages of disease. We conducted an exploratory study to characterize ED utilization of undiagnosed PD patients to determine how to facilitate their recognition in the ED.