OBJECTIVES: Patients with Parkinson’s disease are frequently treated with levodopa which treats stiffness and tremors. Many patients develop problems with involuntary movements called ‘dyskinesia’ as a result of levodopa medication. Levodopa-induced dyskinesia (LID) can be improved by adjusting the dosage to find a tolerable balance between the benefits and side effects. LID fluctuates in severity throughout the day but there is no reliable way of objectively monitoring patients at home. The intervention is ClearSky’s LID-Monitor which demonstrates the severity of involuntary movements in relation to drug doses, enabling clinicians to make informed decisions regarding altering complex drug regimens. The objective of this study was to assess the cost effectiveness of implementing LID-Monitor in patients presenting with dyskinesia. METHODS:  An early stage cost effectiveness model was developed from an NHS perspective. The decision tree model examined implementation of LID-Monitor compared to current practice over one year. The model considers the incident population, the proportion of patients that are well-controlled or poorly-controlled, the number of falls, healthcare resource use and utility associated with dyskinesia. The model inputs were derived from published literature and clinical expert opinion. Due to the high level of uncertainty, extensive sensitivity analyses were conducted. RESULTS: The results estimated that implementing LID-Monitor resulted in a dominant ICER and a NMB of over £84 million for the whole of England. The costs saved as a result of reducing consultations, reducing hospital monitoring and reducing the number of falls outweighed the cost of implementing LID-Monitor.  Patients also benefitted from an increase in QALYs with an average incremental QALY of 0.13 per patient per year. Sensitivity analysis showed that results were dominant in all plausible scenarios. CONCLUSIONS: The model shows that implementing ClearSky’s LID-Monitor in UK hospitals has the potential to reduce costs to the NHS and increase patients’ quality of life.