OBJECTIVES: Reasons for hospitalisations in people with Parkinson’s Disease (PD) are broad ranging and costly, however detailed analysis of hospitalisations in a large, representative group of PD patients is lacking. This study aimed to explore the reasons for, resource use and associated cost of hospital treatment in participants in the PD MED trial. METHODS: We retrospectively reviewed hospitalisation data from 2,074 patients with PD who were recruited into the PD MED trial from Nov 2000 to Dec 2009 and followed up for ten years. PD MED is a large-scale, “real-life” randomised controlled trial comparing the effectiveness and cost-effectiveness of PD medications. Patients’ demographic characteristics, disease severity, reasons and duration of hospitalisation were analysed. Reasons for hospitalisations were coded based on the International Classification of Disease (ICD-10). RESULTS: Of 2,074 patients, at randomisation, median age was 72 years (IQR 66-77), mean duration with diagnosed PD was 2.8 years (median 2, IQR 1-3) and median Hoehn &Yahr score was 2 (IQR 1.5-2.5). Until Oct 2011, 29% (597/2074) of patients had a total of 941 hospitalisation records. Mean length of stay was 21days (median 9, IQR 3-24). Hospitalisation reasons were classified into 11 categories of PD related conditions and 15 PD unrelated categories. 64.1% of the hospitalisation records can be associated with PD. Main reasons for hospitalisation were: infections including pneumonia and urinary tract infection (18.4%), falls and fractures and other injuries (15.3%), cardiovascular and circulatory disorders (8.7%), central nervous system and disorders of sense organs (8.2%), gastrointestinal disorders (8.0%), and mental health disorders (6.9%). CONCLUSIONS: PD related conditions have a significant and broad ranging specialty impact on hospitalisation rates and associated healthcare costs are substantial. This paper provides economic justification for investing in interventions that manage infection and prevent falls in people with PD